In this paper, a preliminary numerical method is established to simulate the effect of nonequilibrium plasma in water vapor on the nucleation rate of condensation. In this model, the plasma drift-diffusion model is employed to describe the water vapor plasma by considering a set of simplified reaction mechanisms. A heterogeneous condensation model describes the rate of water vapor nucleation on ions. The numerical simulation results show the formation and distribution of charged particles in nonequilibrium plasma and the effect of charged particles on the nucleation rate. The results also show that the nucleation rate increases rapidly with increasing supersaturation due to the presence of nonequilibrium plasma and is significantly higher with plasma than without plasma. The process of plasma-enhanced water vapor nucleation can be simulated quantitatively by this preliminary numerical method.