Control method and device for reducing power switching time

The present invention relates to a control method and device, which provides two control circuits, and the first control circuit is used to output a stable control signal for making the output of the power output device at the target value; and the second control circuit is used for feedback control based on the output value of the power output device. There is provided with a switch to connect the power output device with the first control circuit at the beginning of connection for the power output device to receive the stable control signal, so as to output the target value in a short period of time. It is then switched to the second control circuit for feedback control on the power output device. The present invention could be applied for controlling the reading and writing power on the output of an optical reading and writing system, and for reducing the time of power switching at the beginning of switching to the reading and writing states, and further ensuring the accuracy of data reading and writing.