Aiming at the problems of poor forming accuracy and low surface quality in sand mold additive manufacturing， this paper systematically studies the relationship between printing process parameters and sand mold surface roughness， and verifies the feasibility of sand mold printing adaptive slicing for optimizing sand mold surface quality. The influence of resin content， layer thickness and sand mesh on sand surface roughness is studied by designing the response surface experiment of sand print with constant inclination angle， and the printing process parameters are optimized. The orthogonal test of sand print with variable inclination angle is designed to study the significance of layer thickness and print angle on sand surface roughness， and the impeller sand mold is selected to verify the adaptive slicing process. The results show that the surface quality of sand mold with constant angle is better when resin content is 2.08%， layer thickness is 0.3 mm and sand is 100/200 mesh. When the sand mold with curvature change in the vertical direction is printed， the printing angle has a great influence on the surface roughness of the sand sample. An adaptive slicing process is proposed to print the impeller sand mold. Compared with the sand mold prepared by traditional equal thickness stratification， the dimensional accuracy and surface roughness of the sand mold with adaptive layering are increased by about 51.03% and 30.11%. The basic process control research based on the surface roughness of sand mold printing is carried out. The relevant research conclusions are helpful to realize the high precision and high efficiency additive manufacturing of sand mold with complex structure.