In this paper, the heat balance integral method was employed to solve the internal temperature of ice layer and the position of melting interface by stages, due to its main advantage of converting the governing partial differential equation to an ordinary differential one, which can effectively reduce numerical efforts. Then the deicing time of hot water for insulator was calculated and analyzed. Taking LXY-120 insulator as the verification object, after natural icing at Xuefeng mountain natural icing test base, the validation experiments of deicing time were carried out in the natural environment. The initial water temperature and outlet pressure were optimized for deicing efficiency. Finally, the leakage current of water jet was measured. The research results indicate that the deicing rate increases and the energy consumption gradually decreases as the initial temperature of hot water increases. As the outlet pressure increases, the deicing rate increases. For the deicing condition of 1.2 mm nozzle, ambient temperature of -1 °C, wind speed of 3 m/s, ice weight of 2 kg/piece and deicing distance of 2 m, when the initial temperature of hot water and outlet pressure are 85.21 °C and 3.35 MPa respectively, the comprehensive deicing efficiency is the highest. The leakage current through water jet decreases with the increasing distance. The leakage current increases with the increase of water conductivity and outlet pressure. Hot water deicing for insulator in 110 kV system can be carried out according to the safety distance of the existing regulation.