Aiming at the stability and accuracy of the mapping and positioning of the Automated Guided Vehicle (AGV) in longdistance driving and complex environments , a post-processing method using graph optimization and filtering is proposed. A terminal optimization algorithm, when this algorithm is optimized, it will give priority to extracting the reflective column information. When the reflective column information is not detected at the front end of SLAM , the system will use the conventional graph optimization algorithm for positioning and mapping. After detecting the reflective column and obtaining the coordinates of the reflective column, the system will switch to the extended Kalman filter. (Extended Kalman Filter, EKF ) algorithm to locate the AGV . It has been verified by experiments that when the system travels long distances through special scenes that are difficult to locate, such as open spaces, complex environments, or frequent changes in the environment, the positioning accuracy and robustness of the SLAM algorithm that alternately uses natural environment information and reflective column information can achieve certain improvements.