China is rich in walnut meal resources, the protein content of walnut meal is high, but it has not been fully utilized. Low fat food is in line with people’s health consumption concept, but it often has some problems such as high hardness, low moisture content, poor taste and flavor. Walnut protein was prepared from walnut meal by appropriate enzymatic hydrolysis technology, and the walnut protein was applied to the processing of prepared food to explore its influence on the quality of prepared food. The results showed that the walnut protein prepared by moderate enzymatic hydrolysis technology could significantly improve the quality and the cooked yield of prepared food. This study can provide technical support and theoretical basis for making full use of walnut meal resources and developing new low-fat conditioning food.