Missile formation baseline measurement is the premise of missile cluster attack.In view of the problems in missile formation baseline measurement, a high-performance lightweight baseline measurement method is proposed based on BDS-3 DGNSS/RDSS/INS.Taking the BDS RDSS short message as a formation data transmission link, a pseudo-range single-difference observation model is established based on the BDS-3 DGNSS/INS. Under conditions of continuous normal GNSS signal or signal interruption, the DGNSS and INS integrated navigation is capable of achieving a stable baseline measurement output.The simulation results show that the DGNSS/INS integrated navigation can achieve stable baseline measurement output in the observation epoch of continuous normal GNSS signal. With the GNSS signal interrupting in 20 seconds, the baseline measurement error of DGNSS/INS integrated navigation in the east (E) and north (N) directions is less than 2.5 m(1σ), and the baseline measurement error in the up (U) direction is less than 3.0 m (1σ). The requirement of pseudo-range single-difference model is reduced by 70%~80% compared with the RTK algorithm.