The invention discloses an anti-loosening plug easy to plug and unplug. The plug comprises a plug body and a socket, the plug body comprises a square base body. Two moving cavities are symmetrically formed in the front end of the base body. Sliding blocks are slidably connected into the moving cavity, the front ends of the sliding blocks penetrate through the moving cavities and are fixedly connected with inserting pieces, rod bodies are fixedly connected to the sides, away from each other, of the two sliding blocks, the ends, away from the sliding blocks, of the rod bodies penetrate through the moving cavity and are fixedly connected with buttons, and storage grooves matched with the buttons in shape are formed in the outer side of the base body. The plug has the advantages that the distance between the two inserting pieces is gradually increased by utilizing the characteristic that the electrified conductive spring shrinks, and the elastic sheets are respectively extruded, so that the plug body is firmly connected with the socket, and looseness is avoided; and, when the electric appliance is not used, the button can be pressed relatively, a magnetic field force is overcome through the rod body and the sliding block, the two inserting pieces are driven to move relatively to the initial state, and then plugging and unplugging are labor-saving.