An in situ synthesis method was developed to produce a Ni alloy composite coating reinforced by in situ reacted TiN and TiB2 particles using argon arc cladding (AAC) with different molar ratio of BN/Ti on a 35CrMnSi steel substrate. The microstructures of the clad coatings were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results showed that the phases of the coating were TiN, TiB2, TiB, Cr23C6 and γ-Ni. As the BN/Ti ratio increased, the needle-like TiB phase almost disappears and the number of rod-like TiB2 particles increased. Their shape became smaller. The computed results shows that the nucleation driving force of the major reinforcing phases from low to high was TiN-TiB2-TiB at different test temperatures. Moreover, the growth mechanism of the phases is discussed in the Ti-BN-Ni system. The BN/Ti molar ratio was 0.67 showed the highest average micro-hardness and excellent wear resistance at the room temperature under normal atmosphere conditions.