The nucleation theory of charged particles in an external electric field environment is considered. The Gibbs free energy and nucleation rate changes of ion-induced nucleation under an external electric field are studied. The Classical Kelvin–Thomson equation and the ion-induced nucleation theory in the external electric field environment are corrected. The results show that the presence of an electric field can reduce the Gibbs free energy of nucleation and increase the nucleation rate. For particles larger than a few nanometers in size, the impact of the external electric field on reducing the condensation saturation ratio is more pronounced than the combined influence of the Thomson effect and dipole–charge interaction.