This paper aims to study the distribution of temperature field and stress field in laser cladding of workpiece with the curved substrate. In the laser cladding and cooling process, the temperature field and stress field were simulated by numerical simulation. In particular, the laser cladding process was simulated by using the Gaussian heat source model with Ansys software on the outer surface of the substrate of the annulated circular cylinder surface, in which the relative motion was a spiral motion in the processing between the laser head and the substrate. The influence of different power and scanning speed on temperature field and residual stress, as well as the variation of stress field with time and the distribution of residual stress, were analyzed. The results showed that the scanning speed had a great effect on the temperature field. The power and scanning speed had no obvious direct effect on the residual stress. The maximum residual stress appeared in the middle of the outer wall of the workpiece at different power and scanning speed. On the XZ plane, the radial stress showed a funnel shape with high stress around and low stress in the middle. Most of the stress range from +20 MPa to –20 MPa, and the fluctuation was small. On the XZ plane, the circumferential stress was an approximate parabola in the direction of the diagonal, with high values at both ends and low values in the middle. The high value was 100 MPa and the low value was –50 MPa, which fluctuated greatly. In the direction of thickness, the stress distribution was an approximate semi-conical three-dimensional shape. It was an approximately straight line in the direction of the Z-axis, and was an approximate semi-parabola in the direction of the X-axis. It showed that one end is high, one end was low, and the middle part gradually decreased. The high value was 110 MPa, and the low value was –30 MPa, with great fluctuation. It is concluded that the distribution of temperature field and stress field of laser cladding on the curved substrate has been studied successfully, which is helpful to optimize the process parameters and improve the quality of products.