In order to explore the influence of grinding parameters and electrolysis parameters on surface roughness in ELID grinding process, the surface roughness prediction model of ELID grinding was established based on the undeformed chip thickness model by taking into account the randomness of the grit height at the grinding wheel and the influence of the oxide layer in the ELID grinding. Single factor experiments were carried out to study the influence of the parameters of ELID grinding on the surface roughness, and the relationship between the electrolytic current and the thickness of the oxide layer was discussed. In the full factor experiment, the influence of the grinding parameters on the surface roughness was studied by taking the workpiece speed, the grinding wheel speed and the feed depth as the influencing factors, and the prediction model was verified. The results show that in the grinding parameters, when the other conditions are fixed, the surface roughness decreases with the increase of the wheel speed, and increases with the increase of the workpiece speed and the depth of the cutting.At the same time, the prediction error of the roughness is 8.75%, the prediction model is valid and reliable.