The invention discloses an electric shock prevention device used in installation of a lamp tube. The electric shock prevention device comprises a cover plate; connecting plates which are fixedly connected with the cover plate are symmetrically arranged on the lower side of the cover plate; first sliding grooves are formed in opposite sides of the connecting plates; a connecting terminal which is in sliding connection with the first sliding groove is inserted into each first sliding groove; each connecting terminal is composed of conductive metal; grooves are formed in the opposite sides of theconnecting terminals; and a cavity is formed in each connecting plate. The electric shock prevention device has the advantages that the electric shock prevention device is additionally arranged on aninstallation frame, so that whether a sealed circular ring defined by a fixed ring, a first arc-shaped rod and a second arc-shaped rod is formed or not is controlled; when electrified, the lamp tubeis installed, an electromagnet is electrified to obtain magnetism, and at the moment, the fixed ring, the first arc-shaped rod and the second arc-shaped rod form the sealed circular ring, so that thelamp tube cannot be inserted into the connecting terminal, and the lamp tube cannot be installed under the power-on condition, and an electric shock accident is avoided when the lamp tube is installed; and meanwhile, the damage of the lamp tube can be reduced, and the economic loss can be lowered.