Abstract:Semiconductor laser device demanded on the stability of the power, to the device, small electric shock can cause irreversible damage, thus in the actual circuit application, it must have high performance and security to the circuit.It mainly based on the principle of negative feedback to get the lowest current bias and to stabilize output of current. By using the software of Multisim to simulation the circuit. The constant current circuit module was based on the negative feedback system which was the voltage controlled the current.Compound darlington transistor adopted the structure of the parallel topology, than to find the optimal value of base’s resistance and through the experimental to analysis and verify the accuracy of the proposed method. The simulation and actual measurement results show that to change the value of the positive and negative input voltage in regulating circuit, the value of output voltage was stable. Output current of drive power was continuous and adjustable from 0 1 A.And the stability of output current is very good(Fluctuant value is about 1×10-5A in an hour).