Protective device of security gateway

The utility model relates to a protection device of a security gateway, and relates to the technical field of gateway protection, the protection device comprises an air inlet assembly used for being connected with a gateway shell and blocking an air inlet hole, the air inlet assembly comprises a dustproof net and a cooling plate, and the dustproof net and the cooling plate are arranged on the gateway shell at intervals and located at the air inlet hole; the dustproof net is used for removing dust of air entering the air inlet holes, and the cooling plate is used for cooling the air subjected to dust removal through the dustproof net. The fixed pipeline is arranged on the gateway shell and located at the air inlet hole, the fixed pipeline is provided with the dustproof net and the cooling plate, air enters the fixed pipeline, dust removal is carried out through the dustproof net, then cooling is carried out through the cooling plate, finally, the air enters the air inlet hole, and the interior of the gateway i