A new method for measuring the center position of the thermal physics laser spot has been designed, as traditional methods can cause diffraction interference and result in deviation in the measurement results. Preprocess the thermophysical laser spot image, calculate the second-order differential in the horizontal numerical direction, calculate the threshold through the Gaussian function, realize image enhancement, extract the spot position features, obtain the position coordinates of the spot center, obtain the position coordinates of the thermophysical laser spot center based on the local gray centroid method, and realize the measurement of the thermophysical laser spot center position. The performance test results of the method indicate that the average standard deviation of the azimuth deformation angle measurement results and the elevation angle measurement results obtained by the designed thermophysical laser spot center position measurement method under various indexing table calibration values is 0.39 and 0.17, both lower than the three traditional methods, verifying the effectiveness of the method.