Abstract: A kind of gas drag reduction agent (GDRA), named BIB, was injected into pipeline after atomization. Part of the GDRA was bonded with the inner wall of pipe, and the rest went ahead with the gas flow to the separator in the terminal station. The work efficiency of cyclone and filter separator for the residual GDRA in gas were tested by simulation experiment. The results showed that the cyclone separator with double tangential inlet displayed a higher efficiency upon the atomized GDRA separation. When the distribution of inlet droplets' diameter was constant, separation efficiency for the gas-liquid was increased with the higher inlet gas velocity and larger droplets'mass concentration. The work efficiency of filter separator was more than 99.9%, and it was increased with the larger diameter and mass concentration of droplets. The GDRA would totally be filtered if the diameter of droplet at the inlet was large enough. After two-stage separation, there was little GDRA residue in the gas, which would barely influence the gas supply to the downstream users and facilities of gas transmission. Separator is a junction for GDRA injection, and once the GDRA flows through it, it is necessary to reinject the GDRA to the gas.