Double-color die and method for preparing plastic injection molded parts by using same

The invention provides a double-color die, which has a simple structure, does not need a complete large plastic injection molding machine and has high plastic injection molding efficiency. The double-color die comprises a male die and a female die, wherein the molding face of the female die and the molding face of the male die form a molding cavity, the male die comprises a first male die and a second male die, and a gap is reserved between the two parts; an isolating piece which extends into the molding cavity to divide the molding cavity into a first molding cavity and a second molding cavity, which are not communicated, is arranged in the gap; the first molding cavity and the second molding cavity are communicated with the first pouring runner and the second pouring runner respectively; the isolating piece is connected with a transmission mechanism; and the isolating piece is driven by the transmission mechanism to exit the molding cavity along the gap, so that the isolating piece stays still at a position where the gap at the position of the molding face of the male die is sealed by the surface of the isolating piece.