1. A calculable 3D color printing method, comprising: (1) device initialization: fixing an 3D object at an end of a device capable of lifting and lowering at a constant speed; and calculating a position and an orientation of the object relative to a PVA film using a 3D vision system, namely obtaining a 3D model of the 3D object; (2) virtual simulation: performing simulated calculation with respect to a motion of the PVA film while the 3D object is being lowered at a constant speed; (3) calculating texture pattern on the PVA film: calculating a corresponding relationship between each pixel on the PVA film and an object surface point by the virtual simulation; and obtaining a texture pattern on the PVA film by assigning a color on the object surface point to the pixel on the PVA film; (4) physical printing: printing the texture pattern obtained by the calculating at step (3) onto the PVA film; arranging the PVA film onto water surface at a fixed location; and performing water transfer printing and coloring; and (5) multiple printing: performing water transfer printing operations from varied angles for an object having complex surface geometry, wherein only a portion of the object surface is colored each time, until the entire object surface is colored.