The invention relates to a preparation method for a sprayer with multi inlets and one outlet of a biological material 3D printer, wherein the sprayer is prepared from titanium alloy; the preparation method comprises manufacturing a blank by using laser synchronous powder feeding and material increasing manufacturing technology; the method comprises the following steps of: S1, inputting STL model files; S2, feeding powder; S3, vacuumizing and introducing argon; S4, setting forming parameters, S5, forming a blank; S6: hip treatment; S7: machining; S8, grinding and polishing the inner wall of thefeeding holes and the discharge hole. The sprayer structure is with multi inlets and one outlet, and solves the problems that the existing biological material 3D printer needs a plurality of syringeswhen printing a plurality of materials, the printing is not stable at the joining places, and the material is not continuous. The sprayer is formed by using laser synchronous powder feeding and material increasing manufacturing technology and the forming precision is high.