Protective airtight door

The utility model provides a protective airtight door which comprises a door leaf body and a door frame. The door leaf main body is provided with an auxiliary mechanism, the auxiliary mechanism comprises a worm and gear assembly and a roller assembly, a reducer box body of the worm and gear assembly is fixedly connected in the cavity of the door leaf main body, a worm gear sleeve cavity is communicated with a worm sleeve cavity, an output shaft is sleeved with a worm gear sleeve, a transmission shaft is sleeved with a worm sleeve, and the worm gear sleeve and the worm sleeve are matched with each other; the sliding bin of the roller assembly is fixed in the cavity of the door leaf body, the sliding portion of the supporting seat extends into the sliding bin from the lower port of the sliding bin, the lower end of the output shaft is in threaded fit with the sliding portion of the supporting seat, the lower portion of the supporting seat is a supporting portion, the sliding roller is supported on the supportin