A laser power control circuit includes a system control module for generating two write channel target values in a calibration mode, a driving module for driving a laser generator, and a detection module for detecting two laser power values of the laser generator. A write channel control module of the driving module generates two write channel signals according to the two write channel target values, respectively. The two laser power values respectively correspond to the two write channel signals. The system control module determines a first mapping relationship between a write channel target value and a laser power value according to the write channel target values and the laser power values. The system control module further determines a predetermined write channel target value corresponding to a predetermined laser power value according to the first mapping relationship in a run mode.