Among the various methods to realize the self-propelled gun barrel orientation measurement, the total station measurement method has good comprehensive performance. However, the traditional methods of measuring barrel orientation with the total station have the problems of lack of north reference and axis simulation error. Therefore, a method based on a rotation matrix to measure the accurate orientation of the self-propelled artillery barrel with a total station is proposed. Then, the Euler-Rodrigues formula is used to deduce the deviation formula between the line connecting the marked points and the accurate axis orientation. In this way, the uncertainty model of the accurate orientation relative to each observation could be achieved. Then, to reduce the error of the measurement method, the optimal location of the total station is studied, and the optimal solution is implemented based on the principle of the Monte Carlo method. Finally, a simulated barrel installation experiment is carried out. Experimental results show that the measurement uncertainty under the optimal station layout scheme is within 0. 1, which evaluate the feasibility and accuracy of this method and suppressed the measurement error caused by the station layout scheme.