Disclosed is a TV set standby voice prompt device. The device is characterized by comprising a power supply switch, a system switch, a detection control circuit, a voice circuit, a main control output end and an external electric appliance output end. The control circuit is simple. When the TV set is in a shutdown or a standby state with an output power less than the preset power, the voice reminds the user. The reminding voice enables self-recording. The device is particularly suitable for reminding the aged and the forgetful, allows the electric appliance users to enhance awareness of energy conservation, reminds people to cut off the power supply, and then overcomes problems of standby energy consumption and standby safety. The device is applicable to electric appliances such as TV sets and household audio-video devices, and is used for prompting operation of cutting off the power supply.