The invention discloses a security door safety defending system which comprises a door body. A pressure sensor and a temperature sensor are mounted around the inner side of the front side door plate of the door body correspondingly; a face recognition device is mounted on the outer side of the door body; a control system, an alarming device and a GPRS module are mounted inside the door body separately; the pressure sensor and the temperature sensor are connected with the input end of the control system; the output end of the face recognition device is connected with the input end of the control system; the alarming deice and the GPRS module are connected with the output end of the control system separately; and the GPRS module conducts wireless communication with a household cell phone and an alarming terminal of the public security organ. A storage used for storing correct identification information is mounted inside the door body, and the storage is connected with the control system. The structure is reasonable and reliable, and when a lawless person illegally opens a security door or conducts deliberate sabotage, the system sends out the alarming signal and timely feeds back to the household and the public security organ, so that the loss of property is reduced to the greatest extent.