The invention provides an indoor terminal box of a power supply device. The indoor terminal box comprises a bottom case. The bottom case is provided with a containing region, and the power supply device is placed in the containing region. The power supply device is provided with a grounding metal plate. The two sides of the bottom case are provided with limiting platforms. Each limiting platform is provided with a screw hole. Each limiting platform is provided with a locating column in an extending mode. A grounding metal sheet is detachably connected into the bottom case. The locating column on one side of the bottom case is provided with guide faces which are attached to the transition section of the grounding metal sheet. The locating column with the guide faces extends towards the opposite locating column to form rib plates. The bottom case is further provided with a lead groove for allowing an external lead to be inserted therein. The lead groove comprises a through hole and an elastic lead pressing plate, and the upper end of the elastic lead pressing plate is connected with the upper edge of the through hole. The indoor terminal box has the advantages that the grounding metal sheet is arranged in the bottom case, so that wiring is convenient, and mutual interference will not occur; the connecting and containing structure of the grounding metal sheet is firm, and the conducting stability is good; the tapered screw holes are formed, so connection between the bottom case and the power supply device is stable.