A security management system includes a controlled device to execute a security management method. The controlled device includes a wireless module and a processing module. The processing module communicates with a main controlling device through the wireless module for pairing. When the main controlling device is successfully paired to the controlled device, the processing module executes a security mode. In the security mode, a user directly operates the controlled device. When the controlled device is not successfully paired to the main controlling device, the controlled device cannot execute the security mode, and the controlled device cannot be operated. Therefore, the user only needs to ensure that the main controlling device is nearby; even if the user is at a position distanced from the controlled device, the controlled device may not be operated by others.