Abstract: According to the issue that zero-difference precise point positioning(PPP) augmentation information cannot be directly applied to real-time kinematic(RTK) relative positioning, this paper studies the method of obtaining the zero-difference correction information with PPP ambiguity resolution based on additional coordinate constraint in the reference station, establishes the model of equivalence transformation from zero-difference augmentation information to virtual observation data, and focuses on difference application of state space representation information in equivalence transformation. Experiment designed with real GNSS observation data proves correctness and availability of algorithm according to RTK ambiguity with partial ambiguity fixing technology. The results show that virtual zero-baseline can deliver a good accuracy positioning as same as the network RTK, thereby enabling high unification of regional augmentation system in terms of zone-difference and difference modes.