The invention relates to a preparation method of polyimide, particularly a preparation method of electrically-driven shape memory polyimide. The invention aims to solve the problem of difficulty in direct heating when the shape memory polyimide prepared at present is subjected to specific application. The method comprises the following steps: 1. preparing a diamine mixed solution; 2. preparing random copolymer polyamic acid; 3. preparing a carbon-fiber-containing random copolymer polyamic acid solution; 4. carrying out thermal imidization to obtain a glass plate containing a random copolymer polyimide/carbon fiber mixed film; and 5. cleaning and drying to obtain the electrically-driven shape memory polyimide. Tg of the electrically-driven shape memory polyimide prepared by the method is 220-238 DEG C; the storage modulus is 1.63-1.92 GPa in the Tg-20 DEG C glass state, and the storage modulus is 9.23-11.68 MPa in the Tg+20 DEG C rubbery state. The method can be used for obtaining the electrically-driven shape memory polyimide.