The invention discloses a high-safety and anti-loosening electric power supply device. The device comprises a socket part, a connecting part and a plug part; an inner spiral thread cavity is formed in the portion, close to the left side, of the interior of the socket part, sliding grooves are correspondingly formed in the portions, close to the right side, of the upper inner wall and the lower inner wall of the inner spiral thread cavity, the sides, deviated from the inner spiral thread cavity, of the sliding grooves are each provided with an oblique-angle groove, a sliding guiding rod is arranged in each sliding groove, a sliding block is slidably connected to each sliding guiding rod in a matched mode and slidably matched with the corresponding sliding groove, a first tension spring is wound on the portion, on the right side of the corresponding sliding block, of the outer side of each sliding guiding rod, the sides, close to the inner spiral thread cavity, of the sliding blocks stretch into the inner spiral thread cavity, a first through groove is formed in each sliding block in a vertically penetrating mode, a first containing groove is formed in the center inside each first through groove, first convex blocks are slidably arranged in the first containing grooves, and partition plates are slidably connected in the first through grooves. The device is simple in structure and high in power supply connection stability and has the anti-loosening and anti-electric shock functions, and the safety is improved.