The invention discloses a power supply used for a forest fire prevention all-in-one machine. The power supply comprises an AC24V or DC48V input power supply, a surge suppression circuit and a rectifying circuit, wherein the AC24V or DC48V input power supply outputs power to two switching power supplies which are a first flyback switching power supply and a second flyback switching power supply through the surge suppression circuit and then through the rectifying circuit; the first flyback switching power supply is used for generating DC12V output; and the second flyback switching power supplyis used for generating a laser lighting constant flow source. The laser power supply adopts a full-isolated scheme, and a laser illuminator is protected from being influenced by surge; the valley bottom of a switch tube is turned on by using a quasi-resonance technology, and compared with linear voltage stabilization and hard switching technologies, the conversion efficiency of the power supply can be improved effectively.