Abstract: The thermal state and insulation capacity of ladles with different insulating layer thicknesses were simulated and calculated by building a two-dimensional model of ladles based on the finite element method. A ladle with an insulating layer can effectively improve its thermal insulation. With the increasing of insulating layer thickness, the insulating effect becomes more prominent, but it grows slower. When the insulating layer thickness reaches 20 mm, the preheating time of the ladle is shortened by 1 h, the coal gas is saved by 1 000 m³, and the steel temperature drop is decreased by 6℃ compared with a ladle without any insulating layer. During the heat saturating stage, the outside shell temperature of the ladle decreases by 100℃, and the heat loss at the ladle shell falls down. Due to the insulating layer, the energy of 1 255 680 kJ could be saved per hour, which is equivalent to 43 kg standard coal. A comparison of the calculation results with measured data proves that the simulation results are reliable.