Abstract : In hydraulic transmission, hydraulic oil leakage is a problem that cannot be ignored. If leakage is not resolved, it will not only affect the working performance of the system and damage hydraulic components, but also waste resources and cause environmental pollution. This paper analyzes the leakage forms of hydraulic transmission and the causes of leakage due to poor transmission sealing through the study of sealing mechanism, and proposes effective measures to control leakage, so as to promote the greater role of hydraulic technology in practical work. Keywords : leakage; sealing; countermeasures 0. Introduction Hydraulic transmission uses hydraulic oil as the working medium to transmit power and energy. It has the characteristics of large power transmission, smooth movement, and convenient control, and is widely used in various fields of modern work. In hydraulic transmission, hydraulic oil leakage is a problem that cannot be ignored. If leakage is not resolved, it will not only affect the working performance of the system and damage hydraulic components, but also waste resources and cause environmental pollution. Therefore, the role of sealing device is crucial to the normal operation of hydraulic components and systems. This paper analyzes the failure of hydraulic transmission seals, takes effective measures to control leakage, and promotes the greater role of hydraulic technology in practical work. 1. Types and Forms of Leakage Leakage refers to the phenomenon that fluid flowing or temporarily stored in the cavity of a hydraulic component or system flows out from the high-pressure side to the low-pressure side in small amounts due to pressure, clearance, etc. Leakage is divided into internal leakage and external leakage. Internal leakage is the leakage of the working medium from the high cavity to the low cavity, such as the leakage of oil from the high-pressure cavity to the low-pressure cavity in hydraulic transmission, and the leakage from the pressure channel in the directional valve to the return oil channel. External leakage is the leakage of the working medium from the working cavity to the outside of the component and system, such as the end face leakage of the gear pump, the seepage of the hydraulic oil pipe, etc. [1] The main forms of leakage in hydraulic systems are gap leakage, porous leakage, adhesion leakage and power leakage. Leakage Analysis and Countermeasures of Hydraulic Transmission System Full Text Download