Abstract: The important development direction of the environment reconnaissance robot system is to form multi robots network distributing configuration.In the collaboration and navigation of multi robots，the accurate location of robots is very important.With the development of the difference GPS（DGPS），it is very common to be used to locate robots，but with the length of the baseline increasing，the precision of the routine DGPS will decrease.In this paper，the virtual reference station（VRS） is constructed through multi robots system，and the algorithm of DGPS is researched based on the VRS，which can avoid the defect brought by the routine DGPS and make robots move in a large zone with a average and reliable precision.Through the GPS static observation data，the effect of the algorithm is validated.