CFD-DEM model was used to simulate the gas-solid flow in dilute pneumatic conveying with bends. In CFD-DEM, the discrete particle phase was obtained by Discrete Element Method (DEM), and the flow of continuum gas phase was determined by Computational Fluid Dynamics (CFD). In order to consume less simulation time, the effect of the particle solid fraction on the gas phase was not taken into account. The results showed the particle rope formation in the bend and its dispersion in the vertical pipe, and obtained the particle-particle and particle-wall collision information. Comparison of the collision information in the bend, the collision and abrasion seemed more intensive at the bottom of the bend. It was also found that the geometry and parameters have different magnitude effects on the gas-solid flow and collisions in the pipe. The gas velocity was considered to be limited influence on the rope dispersion, but significant effect on the collisions in bend section. With the increase of the solid mass flow, the particle rope seemed stronger and more dispersed at a low rate, and there was a shield formed to impede particle-wall collision at the bend section. The increase of the bend radius ratio also made the particle rope stronger, and the dispersion rate lower.