On the basis of analyzing the research status of spatial angle measurement methods and devices at home and abroad, a new spatial angle measurement method based on photoelectric tracking platform is proposed. The photoelectric tracking platform is installed on the target through rigid connection of mechanical structure to establish the spatial coordinate relationship between the target and the photoelectric tracking platform, and between the photoelectric tracking platform and the earth. When the spatial angle of the target changes, the tracking angle of the cooperative target plate by the photoelectric tracking platform can be used to calculate the spatial angle change of the measured target through the spatial coordinate transformation relationship between the platform and the target. Taking the measurement accuracy of artillery adjustment as an example that the spatial coordinate system is established. The mathematical model of spatial rotation angle of the measurement method is established by utilizing the coordinate transformation relationship between the measured object, cooperative target and photoelectric tracking platform. The photoelectric tracking platform, miniaturized high-precision turntable and cooperative target plate are used to construct the simulation experiment of the measurement of the spatial rotation angle of the artillery barrel. The mathematical model of spatial rotation angle is used to calculate the experimental results and analyze the experimental errors. It is proved that the mathematical model of spatial rotation angle for this method which is effective for measuring the spatial rotation angle such as the accuracy of artillery adjusting and so on.