A full bridge converter having a wide output voltage range includes an input power source, a full bridge switching circuit, a transformer, a first rectifying circuit, a second rectifying circuit, a first output circuit, a second output circuit, and a control circuit. The transformer includes a magnetic core, a primary side winding, a first secondary side winding, and a second secondary side winding. The first rectifying circuit includes a first AC switch, a second AC switch and a first freewheeling diode, and the second rectifying circuit includes a third AC switch, a fourth AC switch and a second freewheeling diode. The control circuit, according to a duty cycle, controls the first AC switch and the third AC switch to be turned on during a positive half cycle, and controls the second AC switch and the fourth AC switch to be turned on during a negative half cycle.