High-speed mechanical devices are more and more widely used in modern industry. In view of the thermal accumulation effect of high-speed mechanical devices under extreme working conditions, this paper utilizes the basic principle of spatio-temporal coupled generalized finite difference method to derive the thermal distribution at different locations by Taylor expansion and moving least squares method at separate points. Combined with the Gaussian distribution laser heat source model, the dynamic reconstruction of the thermal field of the device is realized. The study shows that the horizontal error between the solution result of the finite difference method and the actual simulation result is no more than 10 m, and the vertical error is no more than 0.5 m. And the temperature of the X-axis is no more than no more than 1.0 K, and the temperature of the Y-axis has no error. Combined with the solution results for thermal field reduction, the error of thermal field reconstruction is minimized when the reduction angle is set to 145.26°.
