To investigate the influence of forming outer circle grinding process parameters on the surface quality of 18CrNiMo7-6 gear steel， and determine the optimal combination of process parameters， this paper uses universal tool grinder and CBN forming grinding wheel to process a V-shaped notch by forming grinding. Taking the workpiece speed， the grinding wheel speed and the grinding wheel radial feed speed as the test variables； the three-dimensional surface roughness amplitude parameters： surface roughness， root mean square roughness， surface skewness and surface kurtosis are used as the evaluation process indicators of surface quality. Single-factor experiments and orthogonal experiments are conducted separately. The experimental results indicate that as workpiece speed increases， surface roughness， root mean square roughness， and surface skewness all decrease first and then increase， while surface kurtosis gradually decreases； as grinding wheel speed increases， surface roughness and root mean square roughness also decrease first and then increase， while surface skewness and surface kurtosis increase first and then decrease； as grinding wheel radial feed speed increases， both surface roughness and root mean square roughness gradually increase， while surface skewness and surface kurtosis first increase and then decrease. The degree of influence of the three variables on the three-dimensional surface roughness of the workpiece， ranked from greatest to least， is： grinding wheel speed， grinding wheel radial feed speed， and workpiece speed. The optimal parameter combination identified from the comprehensive single-factor experiment and orthogonal experiment results is as follows： a workpiece speed of 900 r/min， a grinding wheel speed of 5 000 r/min， and a grinding wheel radial feed speed of 0.15 mm/min.