A power off method for a wireless device is proposed. A battery is installed in the wireless device as the power supply. When the power source is connected to the wireless device, an identification process is conducted between the wireless device and the wireless receiver connected to a computer. After the completion of successful identification process, the control chip within the wireless device stores a set of ID code that can be identified by the wireless receiver. In order to prevent wireless devices from being inadvertently reactivated, these devices are usually turned off during traveling. The present invention provides a power off method that terminates power to all parts of the wireless device except the control chip by a certain operation on the connect button. Therefore, an individual power switch is not required while the device can be turned off, and resume the normal operation on the next power on.