The study aims to remove the excess welding layer by electrochemical machining to avoid secondary damage on the welding surface caused by manual grinding. Through the simulation and experimental study on the removal of the weld joints after TIG with Hastelloy-X as base metal. The three-dimensional and two-dimensional simulation models are established to analyze the distribution of electric field, flow field and heat generation power consumption in the processing area, as well as the change of welding layer profile with processing time. The proper electrochemical machining parameters for removing welding layer were selected by orthogonal test. The results of simulation and experiment are compared to analyze the reasons for the deviation between theoretical value and measured value in the process of removing welding layer. The simulation results show that the erosion removal rate of the weld center is significantly lower than that of the two ends of the weld joints under the coupling of electric field, temperature field and flow field, and the morphology of the erosion removal groove becomes more obvious with the increase of processing time; The two-dimensional model can accurately characterize the change of electrolyte rate on anode surface in machining clearance. Based on the orthogonal test, it is found that the voltage and frequency of electrochemical machining have a significant effect on the removal of welding layer, and the duty ratio has little effect. When the processing voltage is 30 V, the average surface roughness reaches a minimum of 19.2 μm, and the removal amount is 0.241 g. The profile morphology after the removal of the welding layer is consistent with the trend of the simulation results, which can accurately characterize the process of removing the Ni-based alloy welding layer by electrolytic machining method, and can realize the mutual optimization of simulation and experiment.