Objective To develop an optimal pulse electrochemical polishing technology to improve the surface quality of Ni5% W alloy substrate. Methods Using environment friendly phosphoric acid and glycerol buffer additives as the polishing system. Pulse electrochemical polishing technique was used to study the influences of pulse parameters, namely current density, pulse frequency and pulse duty cycle on the surface polishing effects of NiW substrate. The microstructure of the polished substrate surface was characterized by scanning electron microscope and atomic force microscope. The best pulse electrochemical polishing process was obtained according to the test results. Results The best pulse electrochemical polishing process conditions were as following: Jm = 25 A / dm2 , f = 1000 Hz, duty cycle 1:4, t = 10 min. The SEM test results showed that the baseband surface was smooth and compact after polishing. Rolling and heat treatment defects such as streaks and grain boundary were eliminated. The surface roughness of NiW substrate was effectively reduced and the surface quality was improved by the optimized polishing process. The AFM tests results showed that the average surface roughness was a few nanometers within the 4 μm×4 μm range, showing that the polished substrate surface was very smooth, reaching mirror state. Conclusion The optimal polishing process could significantly improve the surface quality of the substrate and achieve good substrate surface state. It could meet the requirements of coated conductor on the surface quality of metal substrate materials.