A flashlight tamper-proof structure for preventing a lamp cover fastened to an end of a flashlight from being unfastened manually includes an appropriate section of an end of an opening of a body of the flashlight extending to form a carrying portion; an internal thread section penetrating a front end of the carrying portion; a hole formed at a corresponding point of a rear end of the carrying portion, to allow a screw to be inserted into the carrying portion and screwed to the internal thread section with a tool; and concave indentations formed at the periphery of the opening of the lamp cover fastened to the end of the opening of the body of the flashlight The screw screwed to the internal thread section is moved forward with the tool to reach the concave indentations.