Abstract: Since the existing SLAM algorithm can not meet the actual demand of the Mars rover autonomous navigation problem in real-time and accuracy, a distributed EKF-SLAM algorithm is proposed based on heading assistance to achieve the rover's autonomous navigation. The solar azimuth is got by using the dual axis analog sun sensor, and then the rover heading information is calculated and added it to each subsystem of SLAM. Consequently, a SLAM model of EKF-SLAM system is built and the federal EKF is adopted to realize the state estimation of the distributed SLAM system. Finally, a whole astronomical heading assistant distributed system is constructed. The experiment test is performed in outdoor experimental environment using a mobile robot, and the experimental results demonstrate the accuracy and effectiveness of the proposed algorithm.