Abstract: The numerical model of the temperature field of wire arc additive manufacturing is simulated by Workbench. Through combining birth and death method with the mobile heat source, the temperature field under different process parameters is established and solved. The results show that the heat accumulation effect in the multi-layer additive process of formed parts is enhanced layer by layer under fixed input conditions. Under the same heat input, the temperature of midpoint on weld bead increases from 2 354.9 ℃ in the first layer to 2 879.7 ℃ in the tenth layer. The heat accumulation can be reduced by controlling the cooling time and changing heat input. The interlayer temperature is controlled below 600 ℃. And the maximum temperature of the additive process is reduced by 10 % by changing the layer-by-layer heat input parameters.