A method and system for detecting, recognizing, and automatic disarming of an alarm control unit (3) for monitoring a secure space that is closed by at least one door, the system including the control unit (3), at least one autonomous detection and identification assembly including a proximity transmitter/receiver (4b) and at least one detection sensor (5b) making it possible to detect an opening of the door and/or a passage through the latter, and at least one active wireless communication portable medium (6) including an identification code. The method includes, following detection, in the armed state of the control unit, controlling the activation of the transmitter/receiver to activate it, then to deactivate it, after a predetermined time t0, to put it on standby and, in the disarmed state, to keep it on standby.