By establishing a three-dimensional coupled mathematical model, the effects of the current intensity and the depth of the electrode inserted into the slag pool on the temperature field and electromagnetic field during the electroslag remelting(ESR) process of G20 bearing steel were investigated. The magnetic field strength is mainly concentrated on the outer surface of the ingot. Due to the high electrical conductivity of the slag, the Joule heat of the system is mainly generated in the slag pool, and the highest temperature is located in the center of the slag layer. With the increase of current intensity, the current density of the whole system increases and the temperature increases. And with the electrode insertion depth increased from 10 mm to 30 mm, the temperature of the system showed a downward trend. At the current intensity of 1 500 A and the electrode insertion depth of 0.1 m, the maximum temperature of the central axis of the system is 2 187 ℃, and the average temperature of the slag-gold interface is about 1 600 ℃, which are all greater than the liquidus temperature of the steel ingot, which is 1 493 ℃. The molten molten steel passes through the slag layer and gradually solidifies to form an ingot, which can provide a theoretical reference for actual production.