Abstract: In order to obtain high accuracy of high elevation, long baseline structure is normally used for Interference Synthetic Aperture Radar (InSAR) system. The dynamic and high accuracy measurement of long baseline is necessary. In this paper, a method for dynamic measurement for long baseline using single camera and laser rangefinder system based on distance constraint is proposed. It realizes high accuracy measurement by adding the distance equation to single image space resection mode for constraint. The analysis of principle and experiments are carried out in this paper. The errors of position and attitude are less than 1 mm and 60 arc-seconds obtained by this method in about 50 m photography distance. Experiments show the validity of the method.