Abstract: Diesel engine is an indispensable power source in China's agricultural production, and there are various types of agricultural diesel engines, which have good economy and strong adaptability．In recent years, with adjustment of China's diet structure, the state has implemented "grain feed" and "grain livestock", and livestock husbandry industry based on beef cattle breeding has been vigorously developed, mechanized farming is an important support for modern beef cattle breeding, and agricultural machinery powered by diesel engine in all aspects of farming has been widely used．Taking beef cattle breeding as an example, supporting application of agricultural diesel engine in grass production, harvest, processing, beef cattle feeding and waste treatment were expounded, and problems of poor working stability, large noise and emission in development of agricultural diesel engine were analyzed．Development strategies of improving performance of agricultural diesel engines by using advanced technologies such as electronic control and high pressure injection, making matching adaptability between agricultural diesel engines and specialized agricultural machinery and tools, strengthening manufacturing process of agricultural diesel engines and strengthening production process management were further proposed．