Abstract: Arc welding power supply in the welding process,the current signals are vulnerable to internal and external factors,so that the current signal noise is particularly complex,and high quality welding current signal is very important for the digital power supply control system.According to interference with complex and diverse characteristics of twin-wire current signal,a welding power source was proposed based on gradient Adaptive lattice filter algorithm. Firstly,the gradient adaptive lattice filter was established. The method of gradient lattice adaptive joint estimation was proposed to filter the power signal. By selecting different parameters on different filter effects,the optimal parameters of the filter were determined. Finally,the method presented in this paper was simulated,the simulation results show that the adaptive gradient lattice algorithm can effectively filter out all kinds of noise,and the operation time and smoothness are better.