Ship lock type switching power supply

The utility model discloses a ship lock type switching power supply, including a first-stage circuit, a second-stage circuit, a third-stage circuit, a primary switch, a secondary switch, a first-stage charging capacitor and a second-stage charging capacitor. The first-stage circuit, the primary switch and the first-stage charging capacitor are sequentially connected in series; the second-stage circuit is connected in parallel to two ends of the first-stage charging capacitor, and the second-stage circuit, the secondary switch and the second-stage charging capacitor are sequentially connected in series; the third-stage circuit is connected in parallel to two ends of the second-stage charging capacitor; the primary switch and the secondary switch are not switched on simultaneously; and the first-stage circuit is a rectifying and filtering circuit, the second-stage circuit is a pressure relief protective circuit, and the third-stage circuit is a filtering protective circuit. The ship lock type switching power supply in the utility model can block accidental high voltage such as thunder and lightning at a power supply part, thereby effectively protecting electronic equipment.