In this study, the plasma sputtering deposition characteristics of titanium, molybdenum and nickel are investigated by using single crystal silicon wafer as the simulation substrate. It is found that the deposition rates of Ti/Mo/Ni are 7~14, 9~21, 8~16 nm/min, respectively. Scanning Electron Microscope(SEM) shows that the surface particle sizes are 10~20, 50~200, 15~30 nm, respectively. The Mo layer shows ordered grain alignment, and the Ni layer is agglomerated. The deposition efficiency is determined by the smooth surface orientation of the substrate. The deposition rate is 9, 10 and 7 nm/min when the substrate is oriented upward, and 15,18 and 14 nm/min when the substrate is oriented downward. Optimizing the target-sample spacing can increase the sputtering rate, but the target maintenance needs to be optimized simultaneously. Based on the experimental results of silicon wafer, the efficient deposition of Ti-Mo-Ni composite coating on diamond substrate is successfully realized, and the metallization and vacuum sealing of diamond window are completed, which provides technical support for engineering application.