The invention discloses a wide input range dual-bridge LLC resonant converter, and belongs to the technical field of electric power electronic transformation. The inverter comprises an input direct current voltage source Vin, bus dividing capacitors Cin1 and Cin2, switch tubes Q1, Q2, Q3, Q4, Q5 and Q6, a resonant capacitor Cr, a resonant inductor Lr, a magnetic inductor Lm, a transformer T, rectifier diodes D1 and D2, an output filter capacitor Co and a load Ro. By controlling the ratio between the time that the converter works in full-bridge and the tome that the converter works in half-bridge working in one period, an input voltage waveform of a resonant groove is changed, and thus adjusting the output of the inverter is realized. The inverter adopts constant-frequency PWM control, switching frequency is equal to resonant frequency, primary side current is decreased, and conduction loss is reduced. The inverter can realize primary side main switch tube ZVS opening and secondary side rectifier diode ZVS turn-off in a full-input-voltage scope and a full-load-change scope, reduces switching loss, and increases watt intensity. The wide input range dual-bridge LLC resonant converter has the advantages of wide input voltage range, constant-frequency control, benefit for magnetic device design and optimization, and the like.