To realize the automatic orientation and decapitation of shrimp, an integrated device for shrimp orientation and decapitation was designed based on the shape and size characteristics of shrimp, which was mainly composed of oriented rollers, shrimp pushing boards, adaptive clamping claw and knife for the decapitation of shrimp. Three kinds of shrimp of small, medium, and large size were selected. Taking the speed of the shrimp pushing boards, the horizontal speed of the adaptive clamping claw, the rotational speed of oriented rollers and the radius of the oriented rollers as the test factors, and the success rate of the shrimp decapitation as the index, the single factor test and the orthogonal test were carried out to study the effect of each factor on the shrimp decapitation, and then the main parameters of the device were optimized. The results showed that the optimal parameter combinations of the three sizes of shrimp were the speed of shrimp pushing plates of 60mm/s, the horizontal speed of adaptive clamping claw of 70mm/s, the rotational speed of oriented rollers of 60r/min, and the radius of oriented rollers of 20mm. Under the optimal combination of parameters, the device has the highest decapitation success rate and the success rate of shrimp decapitation was 91.5% for small shrimp, 94.6% for medium shrimp, and 92.8% for large shrimp, the decapitation speed was 36pcs/min for small shrimp, 38 pcs/min for medium shrimp, and 37 pcs/min for large shrimp. Therefore, the feasibility of the device design is verified.