Abstract: In order to analyze the arc spraying deposition process during the mold manufacture the FEA simulation program was introduced to calculate the temperature field and stress field in the sprayed coating.The heat transfer from coating to substrate was taken into account when the mathematical model is put forward.The model is built through the micro-thickness increase of the coatings. The micro-thickness lamellas and method of element's birth or death are activated gradually to participate in the calculation.Movable boundary condition is used to simulate the practical deposition process adequately.On the basis of the calculation, the effect of the stress distribution on the coating unstable and the residual stress is analyzed.