Provided are a method for reducing the power consumption of a power supply, a power supply capable of automatically reducing power consumption, and a television. The power supply includes: a voltage sampling circuit, an optocoupler feedback circuit, a deep standby control circuit, a power supply management circuit and an output rectifier filter. The output rectifier filter includes an output capacitor. The feedback amount (a second level or a first level) of the optocoupler feedback circuit changes as the charge amount of the output capacitor changes, intermittently controlling the power supply management circuit to stop working while achieving a constant voltage output.