Abstract: The research aimed to investigate the flow state and wear characteristics of solid-liquid two-phase flow in vertical curved pipes filled with high concentration gangue-fly ash mixture. A CFD-DEM coupling method based on EDEM was adopted. Cement and water mixed slurry was used as the continuous phase, while gangue and fly ash were used as the discrete phase. The Archard and Oka wear models were introduced to calculate and analyze the wear performance of the filling pipe. The study showed that the coupled method could more accurately reflect the flow state and trajectory of the slurry, and more accurately reflect the interaction between particles and fluids. The high-risk areas for pipe wear were mainly distributed in the curved pipe area. The wear rate of the curved pipe increased with the increase in slurry velocity. The particle size of gangue and the radius of curvature of the curved pipe had an impact on the wear rate related to the force state of gangue particles.