Be used UCC28950 to designing phase-shifted full-bridge converter transformer, achieved the leading- leg and the lagging- led zero voltage switching, which the structure is simple and duty cycle loss is small and the soft switching is easy to implement and so on. First, analyzed its principle from all around, and discussed the condition of achieving soft switching calculated main parameters, then simulated it by using PSIM software. The results prove that parameters are designed reasonably to actual design of 5kW high-power AC/DC switching power converter.