Abstract: Currently, most of the traditional fused deposition molding (FDM) 3D printers can only print monochromatic or dual-color models. To achieve rapid prototyping of multi-color models of 3D objects, a multi-color switching modules that can be installed in any dual sprinkler 3D printer is designed via deeply study the mechanical structures and control logic of traditional FDM 3D printers in this paper. Actual multi-color printing tests show that the multi-color switching module fabricated based on design schemes can accurately and stably complete the rapid prototyping of the multi-color model 3D objects. Experiments show that the printing quality of the products is better under the printing temperature of 180 ℃ and the printing speed of 200 mm/s. This work provides new ideas for FDM multi-color 3D printing.