For prawns in open back processes, and lack of practical equipment, taking Litopenaeus vannamei as research object, the key technology of prawn back opening was studied, the factors affecting the effect of back opening were analyzed, and the evaluation index requirements were established, in the rotating disc prawn open back device was carried on the three factors three levels of response surface optimization test, and the optimized drive back parameters were obtained. A validation test was carried out. In order to study the main influencing factors of open-back process of prawn, a mechanical model of open-back process of prawn was established. The main influencing factors were tool angle, machining center disk speed and tool placement distance. The optimal range of influencing factors was determined by single factor test as follows: tool angle of 20°~60°, machining center disk speed of 10~40r/min and tool placement distance of 9~11mm. Based on Box-Behnken central composite design theory, the three-factor and three-level response surface test was designed, and the test data were analyzed and optimized. The theoretical optimization results were as follows: under the conditions of 43.838° tool angle, 28.391r/min tool rotation speed and 9.801mm tool positioning distance, the success rate of back opening, shrimp damage rate, shrimp line naked success rate and sensory score were 99.161%, 2.825%, 90.727% and 86.944. Verification test results showed that for medium Litopenaeus vannamei, when the tool angle was 45°, the processing center rotation speed was 28r/min, and the tool placement distance was 9.8mm, the success rate of back opening was 98.89%, the damage rate of shrimp was 3.33%, the success rate of shrimp line exposure was 87.78%, and the sensory score was 85.33 points, and the absolute error between them and the theoretical optimization value was small. The reliability of the regression model prediction was proved, and the performance of the optimized prawns open-back device met the operation requirements.