The invention relates to a microwave power supply and particularly relates to a high-power microwave power supply capable of efficiently dissipating heat. The power supply comprises a first rectification filtering module, wherein the first rectification filtering module is connected with a resonance half-bridge circuit module for generating an alternating signal, an output end of the resonance half-bridge circuit module is connected with a primary winding of a high-frequency transformer, a secondary winding of the high-frequency transformer is connected with a second rectification filtering module for rectification and filtering, the resonance half-bridge circuit module is connected with a driving module, the resonance half-bridge circuit module comprises a first switch Q1 and a second switch Q2, and the driving module drives the first switch Q1 and the second switch Q2 to be switched on or switched off to generate alternating signals on the primary winding of the high-frequency transformer. The power supply is advantaged in that the defect that in the prior art, heat dissipation performance of a high-frequency transformer is poor in the prior art can be effectively overcome.