A mobile robot localization method based on the monocular vision is proposed. According to the planar ground assumption, a plane homography-based mobile robot pose estimation model is established with the KLT corner detection and tracking algorithm. Under the framework of random sample consensus algorithm, the initial location of the mobile robot is realized by solving the above model. On this basis, a triangular structure of corner features is adopted for plane parameter estimation. Combined with M-estimation algorithm,the non-planar feature information is excluded efficiently and the location accuracy of mobile robot is improved.The indoor experimental results demonstrate the effectiveness and feasibility of the proposed algorithm.