Security door

The utility model belongs to the technical field of security doors, and discloses a security door which comprises a security door body. The anti-theft door body comprises a bulletproof plate layer, afirst installation door body layer, a second installation door body layer and a heat dissipation plate layer. The bulletproof plate layer, the first installation door body layer, the second installation door body layer and the heat dissipation plate layer are connected in sequence. A sensing device for sensing harmful gas is arranged on the first mounting door body layer; an anti-theft device is arranged on the second mounting door body layer; the sensing device comprises a third processor, a smoke sensor, a toxic gas sensor, a power supply module and an alarm device; and the third processor is connected with the smoke sensor, the toxic gas sensor, the power supply module and the alarm device. The protective cover has the characteristics of reliable and stable protection and multiple functions. 本实用新型属于安防门技术领域，公开了一