The invention belongs to the field of solar cell manufacturing equipment and discloses a solar cell coating power supply device. The solar cell coating power supply device comprises a wire, a cable box, a nut, a rotating shaft, a connection rope and a cooling structure. The cooling structure is arranged in the cable box. One side wall of the cable box is provided with an inlet and an outlet. The rotating shaft is divided into a thread section, a winding section and a rotation section from the up down in sequence. The rotation section is in rotation connection with the bottom portion of the cable box; the thread section is in threaded connection with the nut; the nut is in slide connection with the cable box; and when the nut slides, the nut can drive the cooling structure to realize cooling. The middle portion of the wire is wound on the winding section; and the end portions of the wire pass through the inlet and the outlet. The cable box is internally provided with a spring. One end of the spring is fixedly connected to the side wall of the cable box, and the other end of the spring is connected with one end of the connection rope; and the other end of the connection rod is fixedly connected with the rotation section. The device can change the length of the wire used for power supply as needed, and can prevent damage to the wire due to long-term bending and the like.