The machining process produces surfaces that require some form of finishing operation to improve the surface quality. Aiming at the problem of effective finishing for rough surface, the two stages high frequency short pulse electrochemical mechanical finishing (PECMF) technology is proposed. The composition of test equipment and principles of constant pressure regulating in flat and curve surface finishing process are discussed respectively, and the electrochemical finishing device and a series of cathode tools are designed. Systematic process parameters experiment for superalloyGH188 is carried using Taguchi methodology, the technology rule of process parameters on surface roughness is analyzed and a set of optimized process parameters were obtained. The results have shown that the constant pressure PECMP technology can significantly improve the surface roughness to Ra0.2175μm. The interaction effect between electrochemical anodic solution and mechanical polishing is important for improving the surface roughness in high frequency short pulse electrochemical mechanical finishing process.