The invention discloses a device and method for controlling a power source. The device comprises a processor and at least one remote control unit communicated with the processor. The remote control units are used for sending power-on control signals or power-off control signals to the processor. When the processor determines that all the remote control units send the control signals, and all the control signals are the power-on control signals, the processor controls the power source to be powered on. When the processor determines that the signals sent by any one remote control unit are the power-off control signals, the processor controls the power source to be powered off. Therefore, before detection, after all operators determine that no faults exist, the power-on control signals are sent to the processor through the remote control units, and the processor controls the power source to be powered on. When any one operator finds out faults in the detection process, the remote control units are utilized for sending out the power-off control signals to the processor, the processor controls the power source to be powered off, and therefore the safety of the detection process is improved.