The invention discloses a preparation method of a polymer electrolyte membrane based on a silicon-based negative electrode material. The method comprises the following steps: dissolving PPC and polymers (at least one of PPMMA, PAN, TPU and PVdF) with polar groups into an N,N-dimethyl acetamide and acetone mixed solution to prepare a uniform and semi-transparent spinning solution; injecting the semi-transparent spinning solution into an injection syringe, carrying out electrostatic spinning for 18 to 22 h with the injection volume of 0.3 to 0.7 ml/h at 15 to 17 kV, and then obtaining a nanometer fiber composite polymer membrane; carrying out vacuum drying on the polymer membrane, and obtaining a polymer electrolyte after electrolyte activation. In the preparation method, the PPC, PMA, PAN, TPU and PVdF serve as raw materials, the cost is low, the resources are wide, and the PPC is a completely degradable material, green and non-toxic. The method disclosed by the invention is simple, high in operability, good in repeatability and easy for industrial production, and has wide application prospect.