In order to improve the sensory quality of scallop, the preservation effect of ultra-high pressure was tested and the color change of scallop adductor muscle under ultra-high pressure was studied. The a*, b*, L* and ΔE of scallop adductor muscle under different ultra-high pressure treatment conditions were obtained by color difference meter and the optimal ultra-high pressure test conditions were found. The experimental parameters were optimized and the experimental design was carried out by using design expert software, and the optimal parameters of scallop adductor muscle ultra-high pressure treatment were obtained. The results showed that when the test pressure was 206 MPa and the pressure holding time was 100 s, the redness value a* of scallop adductor muscle was -5.01, the blue value b* was -12.19, the brightness value L* was 67.12 and the total color difference ΔE was 11.61, close to the initial values of the scallop. The brightness and color difference of scallop adductor muscle have been improved under the action of ultra-high pressure, which provided a theoretical basis for the application of ultra-high pressure technology in scallop processing.