Abstract: The electrical-parameter-control method is brought forward and the double-L power source output characteristic is utilized to realize the goal of one-pulse-and-one-droplet transition of pulsed MIG(metal inert-gas) welding.Digital signal processor-based digital control system model of pulsed MIG welding is set up.The model for simulation is built,and the optimal parameters range is obtained by MATLAB simulation.The simulation experiments on digital controller are carried out.Simulation results indicate that the real-time and accurate adjustment of welding voltage and welding current can be accomplished quickly by the digital controller,but also the control system is able to achieve the control of the double-L power source output characteristic control and droplets transition mode control.