Through simulation of the temperature field variation and residual stress distribution in the molten pool during the process of electro-spark deposition of tungsten coating on steel substrate, this paper aims to better explore the process of electro-spark deposition of tungsten coating and to obtain temperature field distribution and formation mechanism of residual stress during the process. Through the methods of low-speed electrode rotation and up-and-down inching, an anti-ablation tungsten coating is made on the surface of steel substrate from point, line to plane. The temperature field and residual stress of tungsten coating are simulated by ANSYS software. The result shows that the Gauss heat source model can simulate the temperature field distribution and residual stress in the process of electro-spark deposition. On this basis, the temperature field data is put into mechanical analysis model so that the coupling calculation of temperature field and stress field and the stress variation status and residual stress after solidification of tungsten coating in the molten pool are obtained. The simulation results show that with the increase of electro-spark deposition power, the diameter and depth of the molten pool will increase and the peak temperature will increase. The residual stress of the tungsten coating increases with the increase of molten pool temperature. In the process of single row tungsten coating deposition, except the first molten pool, the other molten pools will be affected by the previous molten pool and have obviously less residual stress compared with a single point tungsten coating. The residual stress of tungsten coating formed by multi-row pool group is mainly related to the deposition rate, and the faster the deposition rate, the greater the residual stress.