The work aims to strip 18CrNiMo7-6 gear steel by step with electrochemical polishing method and study the dis-tribution of residual stress along the depth layer. In order to achieve the stripping effect and ensure the surface quality simulta-neously, three kinds of electrolyte applicable to steel were selected and an electrolyte was determined to be used for this experiment according to the test analysis. After the electrolyte was selected, the surface roughness and brightness were used as the criterion to determine the applicable current density and optimal stripping time for 18CrNiMo7-6 gear steel by a single factor test method. The three-dimensional surface topography measurement system was used to measure the micro-step structure of samples and the X-ray residual stress analyzer were applied to study the residual stress of each step so as to obtain the distribution of residual stress along the depth layer. The residual stress at the original surface of the sample was -243 MPa and increased as the stripping depth (15 μm per layer). The residual stress gradually changed from the compressive stress to the tensile stress and then stabilized at about 50 MPa when the depth reached 85 μm. The electrochemical stripping parameters suitable for 18CrNiMo7-6 gear steel were optimized: the electrolyte composition was 20%H2SO4+60%H3PO4+20%H2O, the current density was 0.49 A/cm2, and the polishing time was 25 min. The electrochemical polishing method can be used to strip the surface of gear steel sample by step. Compared with traditional electrochemical stripping methods, the advantage lies in the reservation of each layer surface, so we can retest the residual stress of any layer and study other properties.