A combination measurement system for pitching angles was put forward based on a collimated laser, a single-axis inclinator and a CCD camera to improve the precision and stability of measuring pitching angles in engineering. The combination measurement model was introduced and its combination measurement principle was studied in detail on the basis of the coordinate rotation algorithm and the iteration method. The global sensitive analysis of each factor affecting the combination measurement was carried out by using Monte Carlo method.Obtained results show that compared with the direct measurement method with an inclinator widely used in pitching angle measuring at present, the proposed method can obtain much higher measurement precision and stability. A measurement experiment on a highly accurate three-axis turntable was performed,which indicates that the maximum absolute error is 0.3 mrad and the standard deviation is 0.16 mrad.These data are better than that from the direct measurement method with the inclinator,and meet the requirements of the engineering applications.