Heat transfer model of TiC ceramic coating on 45 steel prepared by electrical discharge coating in liquid was established through finite element numerical simulation method. Heat source model and thermal boundary conditions was selected. The temperature field on the surface of the electrodes was simulated by ANSYS software and the influence of pulse current parameters on the temperature field and coating morphology was researched. The results show that the maximum temperature on the tool electrode is far higher than that of the workpiece. The temperature reduces up quickly in the axis and distributes relatively uniformly in the radial, and the highest temperature declines slowly with the increase of the current. The coating particles like crater deposited on the workpiece are enlarged with the increase of pulse current.