The invention discloses a silicon film with higher carrier transmission characteristics and a preparation method thereof, which relate to the technical field of vacuum coating. The silicon film comprises an amorphous silicon film and CdTe, or CdSe, or CdS and other non-linear resistance materials doped in the amorphous silicon film, and is prepared through a PEVCD technology. PECVD equipment is provided with a plurality of circuits of gas access devices, can simultaneously lead in a plurality of types of gases into a reaction chamber of the equipment for the growth of the doped amorphous silicon film. The invention can ensure that the doped amorphous silicon film is tight and has uniform thickness. Not only the invention improves the carrier mobility of the amorphous silicon film, but also the TFT which is prepared from the amorphous silicon film has equal performance to the TFT which is prepared from low-temperature polysilicon, the preparation cost of a TFT substrate can be greatly reduced, and preparation processes related to TFT are simplified.