Hidden junction box for electrical construction

The utility model relates to the field of hidden junction boxes, in particular to a hidden junction box for electrical construction, which comprises a lower shell, an upper cover plate and a lower shell, the sealing mechanism used for sealing the lower shell and the upper cover plate is arranged in an inner cavity of the lower shell; through cooperative use of a connecting seat, a sealing gasket and a pressing groove arranged on the sealing mechanism, a wire harness is pressed through the pressing groove formed between an upper pressing plate and the connecting seat after an external wire is connected with a circuit element, the dryness of the interior of the connecting seat is kept, and the sealing gasket enters an inner cavity of a lower shell when an upper cover plate is installed, so that the sealing effect is improved. According to the waterproof device, the upper cover plate is arranged on the lower shell, the connecting gap between the lower shell and the upper cover plate is sealed, the purposes of co