The steel fireproof door is composed of the door frame, door leaf frame and door leaf panel made of steel materials. The interior of the door leaf is filled with new environment-friendly flame retardant and thermal insulation materials, and is equipped with fireproof hardware fittings. The steel fireproof door has been treated with fireproof sealing at the junction of the door leaf and the door frame and around the fireproof glass, which greatly enhances the fireproof performance.