Abstract: In view of the fact that network RTK under CORS system can not obtain fixed solution in special environment, a post-processing solution method based on virtual observation data is proposed. The process and steps of generating virtual observation data based on Trimble Pivot platform software and calculating the position of observation points by TBC software network are discussed, and the process and steps of calculating the position of observation points by TBC software network are analyzed. The result of SYCORS example analysis shows that the quality evaluation indexes of virtual observation data are equivalent to the real observation data, and the virtual observation data is verified by practical engineering, which confirms that the virtual observation data has certain reliability.