A method of operating an electronic transmission is disclosed, including the following steps. First, turn on the electronic transmission, initialize settings, and perform as an operating mode. Next, detect whether a setup command, a shifting command, or a shutdown command is received. If the setup command is received, perform as the setup mode; if the shifting command is received, perform shifting; if the shutdown command is received, shut down the electronic transmission. If none of the commands is received for a predetermined period, detect whether a standby function is executed. If the function is not executed, shut down the electronic transmission; if the function is executed, perform as a standby mode, and detect whether to receive any command in a less energy consumption manner. If any command is received, return to perform as the operating mode whereby the method protects, including sustaining the power supply.