The application of electrolytic corrosion in the macrographic examination for stainless steel welding joints is studied,the corrosion solution,corrosion time and output current are selected by experiments. The results show that after being corroded in the corrosion solution consisting of 10 ml nitric acid and 90 ml water for 6 minutes at room temperature with output current of 2 A,a clear macroscopic morphology specimen of stainless steel welding joint is prepared,and the each regions of welding joints can be clearly displayed.