Abstract: A lamp box with a color variable light source comprises a metal halide lamp, a bowl-like reflector, a power source, a filter and a drive motor in its body. The body of the lamp box is connected with optical fibers through a fiber optic plug. The fiber optic plug comprises a fiber optic internal sleeve, a fiber optic position sleeve, a position pole, a holder and a rear base seal sleeve. The fiber optic internal sleeve is settled inside the fiber optic position sleeve. The holder, the fiber optic position sleeve and the fiber optic internal sleeve are fastened by the position pole. Even if the fiber optic position sleeve and the optical fibers in the fiber optic internal sleeve rotate, the fiber optic plug will not depart from the body of the light source lamp box.