Abstract: To improve seed coating quality and meet the seed requirements of modern agricultural production, a new generation of seed coating equipment, model 5BY-5, was developed. An automated control system was designed, with a PLC as the control core and an LCD touchscreen as the human-machine interface, integrating programming, frequency conversion, liquid flow monitoring, and sensor technologies. The main structure, working principle, control system, hardware selection, and anti-interference measures of the equipment are introduced. Human-machine interface software was developed using PRO TOOL/PRO CS, and system monitoring software was developed using the ladder diagram method in the STEP 7-MICRO/WIN environment to achieve component protection, precise metering, automatic control, and user-friendly operation during the coating process. Test results show that the coating qualification rate is 99.2%, and the uniformity coefficient of variation is 0.6%, proving that the equipment can effectively improve coating quality. Keywords : Seed coating machine, automatic control, touch screen, frequency converter, anti-interference 0 Introduction Seed coating is a processing technology that uses seeds as a carrier and coating equipment as a means to uniformly and effectively coat the seed surface with a seed coating agent (usually a gel suspension) containing effective ingredients such as pesticides, fertilizers, and growth regulators in a certain proportion. Most domestic seed coating equipment was developed by absorbing early technologies from the United States, Italy, and Germany, and there is a significant gap compared with advanced international levels. Coating machines that use the lever tipping principle to control seed-pesticide mixing have significant shortcomings in structural design, seed-pesticide supply methods, and metering accuracy control; even the best coating qualification rate is less than 92%. In the early 1990s, a few manufacturers used quantitative pumps and double-door methods for seed coating operations. Although these methods improved the structural principle, they suffered from poor controllability, low precision, and unsatisfactory coating quality. Furthermore, the electronic control systems of domestic seed coating equipment are simple and rudimentary, unable to accurately control seed coating dosage or ensure coordinated operation of various components. This severely restricts the improvement of seed coating quality and makes it difficult to meet the high standards required for seed coating quality in modern agricultural production. [b][align=center]For details, please click: Design and Implementation of Automatic Control System for Seed Coating Machine Based on PLC[/align][/b]