Abstract: A new method that calculates ambiguities in GPS short-baseline through the combination with different carrier phase observations when the deformation is relatively large(0.7 m).A condition that should be satisfied to make sure that the ambiguities of L1 carrier phase and L2 carrier phase are integer,is also drived.The DC algorithm proposed in the reference \ can not only be used to large deformation,but also to the ambiguity resolution in GPS short baseline.Furthermore,the difficulty of the quickness and effectiveness of ambiguity resolution in GPS short baseline,is solved.