Provided is a conversion circuit, including a switch signal input terminal; first and second input terminals; and first and second output terminals. The switch signal input terminal receives a switch control signal. The first and second input terminals receive first and second input signals, and polarities of first and second input signals are different and alternately switch. Depending on the switch control signal, the first input terminal is in communication with the first output terminal and the second input terminal is in communication with the second output terminal, or the second input terminal is in communication with the first output terminal and the first input terminal is in communication with the second output terminal, so that a first output signal outputted from first output terminal has a consistent polarity at any time and a second output signal outputted from the second output terminal has a consistent polarity at any time.