The invention discloses a method for preparing a K418 nickel-based high temperature alloy charging turbine based on a selective laser melting forming technology, and belongs to the technical field ofnickel-based high temperature alloy laser additive manufacturing. The method for preparing the K418 nickel-based high temperature alloy charging turbine based on the selective laser melting forming technology solves the problems of many defects, high cost, long period and the like of a traditional casting process in the development stage of the charging turbine. According to the method, firstly, ato-be-formed material is pretreated, then proper forming powder is selected, a model of the K418 charging turbine is constructed, a program file before forming and machining process parameter settingare prepared and imported into SML equipment, under the argon atmosphere, the SML equipment conducts selective melting on the forming powder material on a workbench according to a scanning path and process parameters in a program, and then according to the set layer thickness, the workbench is lowered by one layer thickness, then the powder is laid, the forming powder continues to be subjected toselective melting, the action is repeated, and the charging turbine is formed through step-by-step stacking. By means of the method, the buckling deformation risk of a charging turbine blade is reduced, and part defects caused by stress shrinkage are avoided.