Due to the influence of regional characteristics, climate environment, customs and other factors, different countries and nationalities have different food cultures. As a complex cultural phenomenon, human dietary life has a very rich cultural connotation. Food culture is an important part of national culture. In the long history of development, due to many differences in living environment, mode of production, social customs, religious beliefs and economic development level, different regions and different nationalities have their own characteristics in terms of diet structure, diet habits and diet nutrition concepts, thus forming a unique diet culture. At the same time, the catering culture with its own characteristics can also reflect the personalities and ways of thinking of different nationalities. Therefore, the purpose of this article is to explore the comparative situation in different cultural environments on the theoretical basis of national cultural psychology and dietary customs, and to analyze the interaction between cultural psychology and dietary culture on the cultural level. This article will use the research method of specific analysis of specific problems to make data comparison and draw a conclusion. The results of the study show that the interviewees believe that a nation's diet customs can represent 76% of the nation's culture. Therefore, from the perspective of the nation's cultural psychology, this paper analyzes the concrete manifestations of the differences between Chinese and western diet cultures, and deeply analyzes the deep philosophical root of the differences, and explores the changes and differences of the nation's cultural psychology behind the cultural differences.