The invention is concerned with a control circuit of electrical source, which relates to one electrical source, one electron device, one mechanism switch, one electron switch and one driving circuit to control the open/ close of electron switch. The mechanism switch has double touch points, when the double touch points moves to left and right to send level signal to driving circuit and electron device. The driving circuit sends another level signal to electron device and opens the electron switch to supply power for electron device, when it receives the level signal sent from the mechanism switch. And the electron device sends cut-off control signal to driving circuit and closes electron switch to stop power supply for electron device, when it receives the level signal sent from the mechanism switch. While it sends holding control signal to the driving circuit and keeps electron device to supply power, when it receives the level signal sent form the driving circuit. It avoids the shortage of large current to the open and close of mechanism switch and reduces the dissipation.