The rotational groove structure is a class of important structure on the mechanical parts. However, it is difficult to finish the surface because of the limitation of the structure. This work aims to realize the finishing of rotational groove structure by electrochemical abrasive belt finishing. Considering the characteristic of the groove structure, the suspension cathode was adopted to control the machining gap. By comparing the difference of the surface topography obtained by abrasive belt polishing with and without electrochemical action and studying the change rule of surface topography during the machining process, the influence mechanism of electrochemical action and mechanical action on surface topography and accuracy characteristics was studied. The influence of process parameters on the roundness and surface roughness was studied to obtain the optimization range of each process parameter by the single factor experiment. The importance of process parameters’ influence on the surface roughness and the roundness was obtained by orthogonal experiment and the extreme difference analysis. The optimum range of process parameters for surface roughness and roundness was determined by the results of single factor and orthogonal experiments. When the abrasive belt was free from axial movement, this method could machine with small gap steadily and achieve the excellent surface quality and precision. The influence of mechanical parameters on the surface roughness is more important than the electrochemical parameters, and the abrasive belt pressure is the most important influencing factor. The influence of electrochemical parameters on the roundness was more important than the mechanical parameters and the current is the most important influencing factor. Electrochemical abrasive belt finishing is an effective method to finish the surface of the rotational groove where is difficult to conduct axial movement of abrasive tool.