The accuracy of an angle measurement system based on interferometric fringe imaging decreases as the measurement range increases. Merely increasing the subdivision factor of precise positioning cannot improve the accuracy of the measurement. In this case, this paper primarily focuses on the parameter design method in non-imaging optical systems and accuracy changes under a wide measurement range. The mathematical models for the dual grating interference system and the wavefront segmentation of the optical wedge array were established, and a parameter design method for non-imaging optical systems under paraxial conditions was proposed. A one-dimensional high-precision angle measurement system was designed, and the measurement error of the system within the measurement range was analyzed and calculated. The results show that the designed angle measurement system achieves a resolution of 0.02" in the paraxial region with a measurement range of [-5°,5°] based on the mathematical model and method proposed in this paper. As the measurement range expands, the precision positioning errors resulting from nonlinear changes in the phase of interference fringes become the primary source of measurement errors. At the maximum measurement angle, the accuracy of the precision axis reduces to 0.42". The above results demonstrate that the proposed model and parameter design method can be employed to design an optical angle measurement system with high accuracy.