Abstract: During hydraulic fracturing in coal seams, the mixing of quartz sand with coal fines increases the flow resistance of fracturing and sand carrying fluids, reduces coal seam permeability, and consequently impairs stimulation effectiveness and coalbed methane (CBM) well productivity. Therefore, investigating the distribution characteristics of quartz sand and coal fines post-fracturing is crucial for alleviating blockages and enhancing CBM recovery. The study combined observations of exposed hydraulically fractured coal seams at mining faces with scanning electron microscopy, stereomicroscopy, and micro-CT analysis to examine the distribution patterns of quartz sand and coal fines and to evaluate how their accumulation affected CBM well production. The results indicated that hydraulic fracturing generated a substantial amount of coal fines through processes including coal rupture, sand-coal friction, embedment, and fracturing fluid flowback. A distinct planar zoning pattern was observed from the distal areas to the near wellbore region, comprising a zone with only coal fines and a mixed zone containing both quartz sand and coal fines. The main fractures were primarily filled with quartz sand and coal fines, while secondary fractures mainly contained coal fines, which were predominantly generated during coal breakage and sand embedment processes. The mixed accumulation of sand and coal fines within the fractures impeded the flow of both water and methane. During the early production stage of CBM wells, when the flow was water dominated or in a gas-water two phase state, coal fines were easily carried into the wellbore. In contrast, during the subsequent gas production stage, coal fines were more likely to deposit within the fractures. The combined clogging effect caused by quartz sand and coal fines was identified as a key factor contributing to gas production fluctuations in CBM wells. These findings provide practical guidance for enhancing permeability through hydraulic fracturing and for optimizing CBM well productivity.