This invention provides a laser power control system to control the power of the emitted laser from an optical pick-up head. The system comprises a temperature sensor and a calculating unit. The temperature sensor is used to detect the temperature of the optical pick-up head and to generate a temperature signal accordingly. The calculating unit, storing a control relation of the optical pick-up head, is used to receive the temperature signal. According to the control relation, the calculating unit calculates and outputs a power control signal under the temperature signal and the setting power. The power control signal, converted from digital into analog by a digital to analog converter, is transmitted to the optical pick-up head, so as to control the optical pick-up head to emit the laser according to the setting power.