A real digital controlled semiconductor laser power supply system is presented.The system use a high-frequency & high-precision digital modulation PWM which is generated by DSP to direct drive power loop,the closed-loop control is completely implemented by software,with high-precision AD the output current has high-precision,low ripple and high dynamic response speed advantages.The system provides seven protections,trouble-lock and fault self-diagnosis functions,it also has a digital remote communication interface.