The present invention discloses a kind of control device for a power supply with zero power consumption in standby mode, which includes a driver, an intermediate relay, a power relay, a signal induction circuit, a working power supply monitoring circuit for controlled equipment, a power switching circuit, a single-chip microcomputer and a battery. When a standby command is received by said signal induction circuit, said single-chip microcomputer causes said intermediate relay to cut off the power supply of the controlled equipment and the power switching circuit by said driver. When the controlled equipment is in standby mode, all parts of the control device of the invention are in the off state but the signal induction circuit is powered by the battery, so as to gain safety with low power consumption.