Abstract: Basing on heat conduction principle of thermodynamics and the equilibrium principle of force and torque in mechanics of materials, one way of thermal stress analysis of an arc rapid forming coating and substrate considering temperature field was proposed to calculate the thermal stress of the coating and the substrate, which caused respectively by the decrease of temperature and the change of temperature field due to the heat conduction of substrate, resulting from the high temperature coating. Basing on generalized heat conduction equation assigned to both initial and boundary conditions, temperature distribution function at different positions in the direction of matrix thickness was derived. On the basis of the temperature distribution function, the temperature strain equation, the force and moment equation, the theoretical formula of thermal stress along with temperature field for coating and substrate was derived. The results showed that the thermal stress distribution between coating and matrix after spray forming can better reflected, also the quality of the coating to achieve thick coating can better controlled by this method.