Variable-frequency power supply capable of preventing plug from falling off

The utility model relates to the technical field of variable-frequency power supplies, in particular to a variable-frequency power supply capable of preventing a plug from falling off, which comprises a power supply main body, a plug main body and a connecting cable, a three-hole socket is arranged on the right side of the front end of the power supply main body, the plug main body is arranged on the inner side of the three-hole socket, and the right end of the plug main body is electrically connected with the connecting cable. A three-hole socket is arranged in the power supply main body, a protective cover is arranged on the front side of the three-hole socket, the protective cover is rotatably connected with the power supply main body, the right end of the protective cover is fixedly connected with a fixing frame, and the rear end of the fixing frame is fixedly connected with an elastic clamping piece. Dustproof protection can be performed on the three-hole socket under the action of the protective cover,