The green design of food machinery is to design and manufacture the food machinery of which life cycle environmental influence is the smallest. It also can be considered to be taking the green technology as the principle to design food machinery. In summary, the green design of food machinery is precisely in the whole life cycle of food machinery to focus on environmental attribute of food machinery, namely, detachability, retrievability, maintainability and reutilization and taking them as design goals, at the same time of meeting the requirements of environmental objectives, ensuring the function, service life and quality that food machinery should have. The purpose of this research is to explore green design methods of food machinery, thereby working out green food machinery, in order to make people feel healthy and comfortable in the process of using. It specifically researches the green design of food machinery material, green design of food machinery structure and green design of hydraulic system and power system in food machinery. And then the comprehensive assessment system of green design of food machinery is established, based on which the conclusion has been reached.