Abstract: Angle measurement is one of the important parameters in the field of geometric quantity measurement. To enrich optical angle measurement technology, an angle measurement method based on the transformation of light wave polarization state is proposed. In terms of theory, two measurement modes, “static front, dynamic back” and “dynamic front, static back”, are constructed. The mathematical relationship between the center displacement of the laser circular spot and the angle measurement in the two measurement modes is mainly discussed. The optical amplification characteristics of the two schemes are compared through the ratio method and MATLAB simulation, and it is confirmed that the “dynamic front, static back” mode has better angle amplification characteristics and higher resolution. In the experimental verification aspect, the distance of three optical paths is allocated under the angle measurement resolution of 0.1" and the minimum pixel of the area array CCD of 3.2 μm. The “dynamic front, static back” measurement mode is used to measure the surface undulation of the 800mm long guide rail, and the displacement data of the light spot is collected in real time. The cumulative height difference of the guide rail surface is obtained by combining the formula, and this measurement result is compared with the data obtained by the autocollimator. The experimental results show that the measurement results of the proposed method have the same cumulative height difference trend as the autocollimator method, and the measurement uncertainty of the angle is 6.67". This verifies the feasibility of the proposed method and provides a reference for the development of a new type of anti-environment interference optical angle measurement system.