The present invention is described for compensating a signal which is transmitted by a transmitting module of the optical disk drive controller through a signal channel and received and reshaped by a receiving module of the optical pickup head to calibrate the duty cycle distortion occurred. The claimed method has the steps of providing a periodic test signal, and then delaying the periodic test signal to form an adjusted test signal and adjusting a delay of an edge between the periodic test signal and the adjusted test signal instructed by a calibration signal. Afterward, the method further has the steps of transmitting the adjusted test signal to the receiving module through the signal channel, and receiving and reshaping the adjusted test signal to form a received signal, and then generating a monitor signal, finally, the method has a step of generating the calibration signal in accordance with the monitor signal.