This paper presents a method for measuring the inclination angle of bearing mounting plane based on binocular vision technology. In the actual installation process of the bearing, the mounting plane will have a certain degree of inclination. To improve the product yield rate, this paper designs the inclination measurement system by using binocular vision technology and the proposed optimised perspective-n-point (PnP) method. After experimental testing, the measurement system for inclination angle proposed in this paper can meet the requirements of the production process. The proposed approach achieves high measurement accuracy as well as good real-time performance.