Objective To further improve the performance of electrodeposited Ni-TiN nano-composite coatings. Methods Sulphamate bath was chosen to prepare Ni-TiN nano-composite coatings on the 3Cr13 substrate using the pulse power in ultrasound environment. The effects of the duty cycle on the nano- composite coatings TiN content, the surface morphology, microstructure and the micro-hardness were studied. Results With the increase of duty cycle, the hardness and nano-TiN content of the coating first increased and then decreased, the diffraction intensity and crystallinity increased while the diffraction peak width of coating texture was narrowed. When the duty cycle was 0. 2, the TiN content reached the maximum of 3. 85% , the hardness of the coating reached a maximum of 580HV0. 1 and the surface of the coating became smooth and dense. Conclusion Smooth, dense Ni-TiN nano-com-posite coating surface could be obtained at certain average current density using the appropriate duty cycle. Co-deposition of nano-TiN affected the crystallization of nickel. The nano TiN contents of coatings prepared under different duty cycles were different, leading to lattice distortion, significant changes in the texture and altered properties of the coating.