The invention provides a power supply device for reducing the standby power consumption of an inverter. When a power unit supplies power to all units of the inverter which need to work in a standby state, a delay unit carries out timing operation so as to provide information processing time for a subsequent load, and a control unit of the inverter is enabled to generate and output a wakening signal when the control unit receives any one of instructions of enabling the power unit to work for a long time. The wakening signal triggers the delay unit to carry out the timing zero clearing and stop the timing operation, thereby enabling the power unit to carry out continuous supply. The inverter can meet the demands of normal functions in a standby state. When the above signal disappears, the wakening unit stops the receiving of the wakening signal, and the delay unit carries out the timing operation again. After the timing duration arrives at a preset duration, an execution unit output a corresponding control signal, and enables the power unit to enter a hiccup state and wait for the next start for power supply. Therefore, the power unit is in an intermittent working state, thereby enabling the subsequent load of the power unit to be also in the intermittent working state, and greatly reducing the standby power consumption of the inverter.