Abstract: The formation mechanism and enhanced condensation mechanism of water vapor nonequilibrium plasma are discussed by the molecular dynamics method. In the nonequilibrium plasma discharge part, the water vapor discharge model is established. Based on this process, the main types of charged particles in the plasma are O⁻, OH⁻ and H₂O⁺. The density functional theory is used to calculate the charge distribution of OH⁻ and H2O⁺. The SPC/E force field was used to simulate the condensation process. The nucleation process induced by these charged particles in the condensation process is calculated, respectively. Compared with the macroscopic theory, the microscopic mechanism of plasma-induced vapor condensation is obtained.