With the development of the power system, the installed capacity of high-voltage circuit breakers will increase significantly. Understanding the causes of high-voltage circuit breaker failures and taking proactive preventative measures is very helpful in improving the reliability of power grid supply. According to historical data and statistical analysis of accident types in the operation of high-voltage circuit breakers in the national power system, failure to open accounts for 22.67%; failure to close accounts for 6.48%; breaking and closing accidents account for 9.07%; insulation accidents account for 35.47%; maloperation accidents account for 7.02%; current cutting accidents account for 7.95%; and external force and other accidents account for 11.43%. Among these, insulation accidents and failure to open are the most prominent, accounting for approximately 60% of all accidents. 1. Insulation Accidents: The main causes of insulation accidents are: firstly, the design and manufacturing quality of the insulation components of high-voltage circuit breakers do not meet technical standards, causing pull rods to detach and preventing proper operation of moving parts; secondly, inadequate tooling and processes during the installation, commissioning, and maintenance of high-voltage circuit breakers. Therefore, strictly controlling the tooling process of high-voltage circuit breakers, inspecting purchased components, ensuring the cleanliness of the assembly environment, and implementing necessary testing methods are important measures to prevent insulation accidents. This must be given high priority by design, manufacturing, and application departments. 2. Failure to Operate and Malfunction Accidents: Failure to operate and malfunction accidents refer to high-voltage circuit breakers failing to open or close, or operating erratically when they should not. Failure to open accounts for over 50% of these types of accidents, making it a major cause. The main reasons are poor manufacturing quality, improper installation, commissioning, and maintenance, and poor secondary line contact. Therefore, user departments should work closely with manufacturing departments to ensure that the design, material selection, necessary spare parts, process requirements, and commissioning guidelines for high-voltage circuit breakers are reasonable and practical, minimizing potential accidents caused by human error and preventing problems before they occur. 3. Breaking and Closing Accidents: Breaking and closing accidents are caused by oil short circuits during the breaking process of oil circuit breakers, severe burn-out of the arc-extinguishing chamber, insufficient breaking capacity of the circuit breaker, and low acceleration after closing speed. Therefore, during the installation, maintenance, and commissioning of high-voltage circuit breakers, it is crucial to pay attention to the exhaust direction of the oil circuit breaker, the grinding of moving and stationary contacts, the removal of foreign objects from the arc-extinguishing chamber, the verification and selection of the circuit breaker's breaking capacity, and the adjustment of its opening and closing speed characteristics. These measures are essential to prevent opening and closing accidents and must not be neglected. 4. Current-cutting accidents: Most current-cutting accidents are caused by poor contact between the moving and stationary contacts. The main reason is poor contact between the moving and stationary contacts or the isolating plug, leading to overheating under long-term high current, resulting in contact melting, burning, loosening, or falling off. Therefore, the selection of materials and heat treatment for the contact springs of high-voltage circuit breakers, as well as the adjustment of contact pressure, are important technical measures to prevent current-cutting accidents. 5. External forces and other accidents: External forces and other accidents mainly refer to oil and gas leaks in the operating mechanism, component damage, frequent pressure testing, irresistible natural disasters, and short circuits caused by small animals. The main reasons are easily aged and damaged sealing rings, poor cleanliness of pipelines and valve bodies, and poor manufacturing and assembly quality of joints. Such problems have long been a major obstacle to the reliable operation of domestically produced high-voltage circuit breakers. 6. Accidents involving vacuum circuit breakers: High-voltage vacuum circuit breakers, with their superior breaking performance and long service life, have been widely recognized by users. With the widespread application of high-voltage vacuum circuit breakers, the improved new generation generally uses longitudinal magnetic field electrodes and copper-chromium contact materials, which plays a positive role in reducing arc voltage under short-circuit breaking current and reducing contact burn-out. However, due to leakage in the arc-extinguishing chamber and bellows, the reduction in vacuum level leads to an increasing number of breaking and closing accidents, which cannot be ignored. Furthermore, reignition and ceramic vacuum tube rupture still occur frequently when disconnecting capacitor banks. At the same time, the current vacuum circuit breaker models are complex, there are many manufacturers, and the product quality varies greatly, posing certain difficulties for users in equipment selection and operation. 7. Accidents involving SF6 high-voltage circuit breakers: SF6 high-voltage circuit breakers, with their good insulation performance and superior arc-extinguishing medium, are widely used in breaking equipment of various voltage levels in power systems. Common problems with domestically produced SF6 high-voltage circuit breakers include: gas leakage, excessive moisture, arc-extinguishing chamber explosion, insulation rod detachment, breakage, breakdown, and horizontal rod pin breakage. Rod detachment inevitably leads to a major accident and must be taken seriously. Foreign objects or components falling out of the arc-extinguishing chamber can cause internal insulation breakdown and flashover in the high-voltage circuit breaker. Therefore, improving the cleanliness of the SF6 high-voltage circuit breaker assembly environment and strictly controlling the process are crucial for ensuring the safe operation of the equipment. 8. Disconnecting Switch Accidents: Disconnecting switches have long suffered from problems such as poor contact, localized overheating and melting, insulator breakage, and mechanism jamming. According to relevant data, these problems remain serious. This necessitates a comprehensive approach, addressing both the symptoms and root causes, from equipment design, manufacturing, operation, maintenance, and management, to overcome this passive situation.