A modeling method of deep dielectric charging in local grounding and heat transfer mode is proposed. Commonly used polyimide materials are selected to simulate irradiation of high energy charged particles in space, and deep charging characteristics of dielectric in local grounding and heat transfer are investigated. Simulation results show that when the temperature ranges from 183.15 K to 363.15 K, the peak electric potential is influenced by the diameter and temperature of the grounding plate. When the temperature ranges from 183.15 K to 273.15 K, the peak field strength is largely influenced by the diameter and temperature of the grounding plate. When the temperature ranges from 273.15 K to 363.15 K, the peak field strength is less influenced by the diameter and temperature of the grounding plate, but there is still discharge risk, and the field strength peak is close to or even more than 106 V/m. Simulation results can provide a reference for the reasonable layout of the thermal control materials and thermal protection and charging protection of solar cell array glass cover sheet.