Abstract: In response to the demand for precise attitude measurement in the production, manufacturing and assembly of large-scale equipment in modern industrial production, a laser tracking attitude angle measurement method based on weighted least squares was proposed. Firstly, the composition of the attitude measurement system was explained, and the coordinate system used in the attitude measurement system was defined; Secondly, the mathematical model of attitude measurement was established, and on this basis, the redundant angle information was data fused using the weighted least square method. The Monte Carlo method was used to simulate and analyze the fusion method; Finally, an attitude measurement experimental platform was built, and the precision of the system’s attitude angle measurement accuracy was evaluated using a precision two-dimensional turntable. The experimental results show that within the angle range of −30°, 30°, the attitude angle measurement accuracy is 0.28° when the measurement distance is 3 m, and the attitude angle measurement accuracy is 1.76° when the measurement distance is 8 m. Compared with the monocular vision method, attitude angle measurement accuracy increased by 6.7% at 3 m and 18.8% at 8 m. The poposed data fusion method has a good effect on improving the accuracy of attitude angle measurement.