Abstract: As the pre-processing process of fish products, pretreatment directly affects the efficiency of fish mechanization processing and product quality. In this paper, the working principle, technical characteristics and research trends of the key processes of fish primary processing, such as de-scaling, de-heading and de-fouling,are described. Based on the summary of the basic processing technology, the research status of fish processing technology and equipment at home and abroad was compared and analyzed, and the future development direction of fish pretreatment processing technology was proposed.