<p>The multi-material composite sand mold can be used to produce high-end complex castings with high efficiency and high precision. Multi-material composite sand mold is manufactured by 3D printing technology with at least two kinds of sands, thereby combining the unique casting properties of each type of sand which can include heat transfer and chilling. This study shows that when the combination position of interlayer composite sand was mixed according to the mass ratio of silica sand and chromite sand 6:4, the strength is higher than the two single-material composite sand. The higher the proportion of silica sand, the higher the overall strength and the better the air permeability of the composite sand mold. Research on 3D printing technology of multi-material sand mold has great significance for preparing gradient functional casting, improving casting performance and saving manufacturing cost. Compared with the silica sand mold, with the increase in the mass of chromite sand, multi-material composite sand mold can improve the microstructures, refine the grain size and subsequently improve the mechanical properties of castings.</p>