TiN coatings are widely used in metal bipolar plate modification due to good corrosion resistance and electrical conductivity.The TiN deposition process is susceptible to formation non-metallic vacancies due to the preparation conditions, affecting the coating properties. Therefore, in this paper, the electronic structures of TiNx systems containing different amounts of nonmetallic vacancies are calculated using the first principle method, and a study of the effect of nonmetallic vacancies on the crystal structure, energy band structure, density of states, relative concentration of free electrons, and charge spreading of each TiNx system is carried out. The analytical results show that with the formation of nonmetallic vacancies, the stability of each TiNx system gradually decreases and the nonmetallic vacancy formation energy gradually increases. The relative concentration of free electrons of each TiNx system is calculated to be in the following order: TiN0.25＞TiN＞TiN0.5＞TiN0.75.The electrical conductivity of the TiNx system is mainly affected by the combination of three factors: the metallization of the 3d orbital state of the Ti atoms, the reduction of the contribution of the N atoms to the 2p orbitals, and the decrease in the volume of the crystal cell due to the deletion of the N atoms.