Abstract: An AC-DC converter and a charge and discharge system thereof are disclosed. The AC-DC converter includes a first signal terminal, an AC signal conversion circuit, a power storage component, a first conversion circuit, a controlling module, a second conversion circuit, and a second signal terminal. The first signal terminal is used for inputting a first power signal. The AC signal conversion circuit is used for converting the first power signal into a first conversion signal. The power storage component is used for amplifying a potential of the first conversion signal. The controlling module controls the first conversion circuit to transfer the first conversion signal into a second conversion signal after the potential of the first conversion signal is amplified. The second conversion circuit is used for converting the second conversion signal into a DC power signal. The second signal terminal is used for outputting the DC power signal.