The invention discloses a PFC and LLC hybrid isolation type switching power supply. The switching power supply comprises a totem-pole PFC circuit, an LLC resonant circuit, a direct-current side capacitor string, an isolation transformer T and a full-wave rectifier, wherein the input end of the totem-pole PFC circuit is connected with an alternating current power supply; the output at one end of the PFC circuit and the neutral point of the direct-current side capacitor string are connected with the inputs at two ends of the LLC resonance circuit respectively; and the LLC resonant circuit is connected to the primary side of the isolation transformer T, and the full-wave rectifier is connected to the secondary side of the isolation transformer T. The totem-pole PFC circuit is controlled by apower frequency square wave signal and a high-frequency PWM signal, wherein the power frequency square wave signal is used for controlling MOSFET transistors in the PFC circuit to be alternately conducted at the alternating current voltage zero crossing point; and the high-frequency PWM signal is used for controlling GaN HEMT devices in the PFC circuit to be alternately conducted. The switching power supply has the advantages of being small in switch loss, high in efficiency, high in power density of the power supply and small in size.