Abstract: A design of digital controlled arc welding inverter system is presented on the basis of studying inverter technique and DSP application technique, in addition, the MATLAB sim-powersystems and fix-point blockset are used to build the simulink model of the power supply system. The simulation system studies the work process of arc welding inverter, the operation process of the algorithm executive system of fix-point controller and the integral characteristics of power supply system. The experimental results have validated the developed simulation model, and this simulation study can accelerate the process of design and development in the coming days.