Sequential solidification process has a great application prospect in casting explosives. In order to study the correlation between process parameters and charge quality， a simulation study of sequential solidification process was carried out， based on the moving boundary modeling method， where TNT/RDX （33.8/65） was taken as an illustration example. The effects of process parameters， such as water injection speed（0.15， 0.20， 0.25 mm·s^-1）， water temperature（30， 40， 50 ℃）and preheating temperature（60， 70， 80 ℃）， on temperature field and shrinkage defects in the solidification process were studied， based on three-factor orthogonal tests， and a optimized process parameter program was obtained. It can be seen that water injection speed has the greatest impact on charge solidification quality， followed by the water temperature and preheating temperature of mold. Compared with experimental program（water injection speed is 0.15 mm·s^-1， water temperature is 50 ℃）， preheating temperature is 70 ℃）， the optimized program of orthogonal tests（water injection speed is 0.15 mm·s^-1， water temperature is 50 ℃， preheating temperature is 60 ℃） reduces the shrinkage volume by 74%. This implies that the matching of process parameters is an effective method in improving charge solidification quality in the future. The simulation results and experimental design methods in this paper can provide references for process parameter matching optimization of charge solidification.