A universal power converter comprises a body and a circuit module. The circuit module includes a power converter circuit; the power converter circuit being a power supply and charging circuit of a power supply; and a voltage adjusting circuit; the voltage adjusting circuit including a main controller; the main controller being installed with a plurality of output ports; each output port being serially connected to a respective transistor and a specific resistor value; each resistor value representing a specific output voltage which is feedback to the power converter circuit; the main controller serving for automatically opening or closing a selected voltage and for driving the signals from the data display screen and the actuating switch.