A current balance circuit includes a first branch and a second branch in parallel between a power supply unit and at least one load, which respectively include a switch. The current balance circuit detects and compares currents flowing through the first branch and the second branch. The current balance circuit also generates triangle waves and reversed triangle waves, compares voltage of a control pole of a first switch with the triangle waves, and compares voltage of the control pole of a second switch with the reversed triangle waves. Then the current balance circuit controls if the triangle waves and the reversed triangle waves are input to the first switch and the second switch according to the currents flowing through the first branch and the second branch to adjust impedance of the first switch and the second switch to balance the currents flowing through the first branch and the second branch.