Abstract: During the development of Coal Bed Methane (CBM), very small particles will enter into the gathering pipe network with gas flow. The existence of particles will result in gas-solid two-phase flow in the pipe, which will affect the pipe characteristics. Gas-solid two-phase flow numerical simulation for the straight pipe and horizontal elbow is conducted with software, the main factors affecting the pressure loss of gas-solid two-phase flow including pipe system characteristics, operation conditions and properties of material are discussed and the speed and pressure distribution characteristics of continuous phase and particle motion trajectory are analyzed. The distribution of pressure field and velocity field of gas-solid two-phase flow and the distribution of particles in pipe and their motion trajectory are obtained as well as the systematic resistance and sedimentation distribution law of particles under different working conditions. This paper carries out numerical simulation analysis according to the dust in CBM pipe on the spot and the result shows that the flow of CBM pipe belongs to low concentration gas-solid two-phase flow and the increase in pressure drop amplitude per pipe length caused by the particles is lower than 2% compared with pure gas phase flow.