Due to the wheel slip phenomenon of the mobile robot in the outdoor environment, the odometer has terrible accumulation errors. The twodimensional laser range finder only scans little environment information, of which the robot would be located in a similar or symmetry environment during the mapmatching process. It leads to the localization failure. According to the above problems, this paper proposed a novel localization method based on the twodimensional laser mapmatching method by using the monocular visual to compensate laser data and odometer data. This method utilizes the monocular camera to collect the color lump data to compensate the twodimensional laser data. The camera is also used as the visual odometer to observe the wheel slip phenomenon, by which the odometer error can be corrected. Finally, particle filter algorithm is applied to fuse the multisensor information. Based on the Pioneer 3AT mobile robot, experiment is proposed in a campus of university. The results show that the proposed localization method has good localization accuracy.