Road information measured by on-board GPS (Global Positioning System) usually needs to compress complex road data, and at the same time selects appropriate road feature points to obtain a high-precision digital map, which is a vehicle integrated navigation system (INS / DR / MM ) provides reference. In this paper, trajectory based on vector can be regarded as the characteristic of a section of a circular arc, infinite circular curve approximation method to study the road feature extraction algorithm based on data points, the curvature radius of curvature calculation, determine the trajectory circle on the step, in order to extract road feature points. Experimental results show that the algorithm improves the efficiency of data compression at the same time, also can reduce calculation and enhance road truth degree.