Finite element simulatin on stress accumulation during the path-by-path depositin process of thermal barrier coating by plasma spraying was performed by FEM software ANSYS12. 0. During the spraying process, the temperature of the deposited coating fluctuates with the movement of the spraying gun periodically within a wide range. This rapid thermal shock will cause a corresponding stress fluctuation. After the coating being cooled to the room temperture, concentrated stress appeared at the edge of the coating, the maximum shear tensile stress existed at the edge of the interface between the ceramic layer and the bonding layer is 122 MPa. Stress at the middle of the interfaces of the coating fluctuates periodically like a wave and stress in the X direction is the major stress.