Abstract: Aiming at the problem that the GPS similar-single-difference model cannot extract the large deformation information, this paper takes full advantage of the three-frequency signal broadcasted by the BeiDou full constellation, A method for quick extraction of deformation information with triple-frequency combination ambiguity resolution and similar-single-difference model based on BDS was studied. Experiments on the high-precision three-dimensional mobile testing platform show that the above method can quickly extract large deformation information. its accuracy is equivalent to that of GPS and can reach centimeter level.