It detects illegal intruders through front-end detection devices such as glass break detectors, infrared detectors and infrared and microwave composite detectors. In the case of any illegal event, it will immediately trigger the alarm control center and display the alarming point on the electronic map for patrolmen’s quick arrival at the alarming point and be linked with the video monitoring system that will switch to the video image of the alarming point automatically and sound an audible and visual alarm to remind the on-duty person of quick handling and record and save the emergency continually. An emergency alarm button can be installed in a concealed way in a specific area for contact with the control center in dangers or other cases needing help. The control center can be networked with the “110” center of public security authorities.