Abstract: Map matching algorithm of factor weighting method、road network topology and grid division is studied in the paper. The process of map matching is analysed,including map data preprocessing、the establishment of road connectivity、the calculation of the projection point and the road matching weight. Next, a map matching algorithm based on road connectivity is proposed,which uses the capture circle to obtain candidate road sets.When the GPS signal is loss, the shortest path algorithm is started to calculate out the way the car passed. Finally, the algorithm mentioned in the paper is compared with others by experiment. It is proved that the algorithm is with high matching accuracy, matching speed and practicability.