Objective To optimize the nickel chloride content, and improve the performance of Ni-nano TiN composite coatings for nickel sulfamate system electrolyte. Methods The effects of different nickel chloride content on the plating solution conductivity and the thickness, microhardness, surface microstructure of Ni-nano TiN composite coating prepared by ultrasonic-electrodepositing method were studied. Results The plating solution conductivity and the thickness, microhardness of the composite coating increased firstly and decreased afterwards with the increase of nickel chloride content. When the content of nickel chloride was 30 g/ L, the bath conductivity was the best and the plating solution conductivity value was 61. 3 mS/ cm, the thickness of the composite coating reached the maximum value of 84 μm, the microhardness reached the maximum value of 760HV, at the same time, the composite coating surface was smooth and the grain size was minimal. Conclusion Nickel chloride content had a great influence on the performance of the plating solution and the composite coating. A suitable content of nickel chloride could prevent anodic passivation, increase the conductive ability of the plating solution, the deposition rate, and the thickness, microhardness of composite coating, refine the grains, and improve the microstructure and performance of Ni-nano TiN composite coating. The suitable content of nickel chloride was 30 g / L.