The reservoir space of dolomite reservoirsfromthe Guanwushan Formation in western Sichuan is mainly composed of vugs and fractures. This study aims to understand the genesis, filling stages and evolution of vugs in dolomite reservoirsfromthe Guanwushan Formation. First of all, through the analysis of the relationship between the developmentalrule of vuggy dolomite reservoirs and sedimentary facies and sequence, combined with research on the sequence of dolomite cement which was formed in the first stage and surrounding rock dolomitization, it is proposedthat the vugs in dolomite reservoirs of Guanwushan Formation in Western Sichuan were formed by facies controlled penecontemporaneouskarstification. According to the analysis of inclusion homogenization temperature, carbon and oxygen isotopes, laser in- situ U- Pb isotopic dating, strontium isotopes and rare earth elements of dolomite and calcite cements in different stages in the vugs, it is suggestedthat the cement in the vugs was formed in a closed diagenetic environment, and the diagenetic fluid was the Middle Devonian seawater transformed by the addition of underlying clastic rock formation water. The reservoir space of dolomite reservoirs of the Guanwushan Formation has experienced three evolution stages: the formation stage of vugs and fractures before dolomitization, the formation stage of surrounding rock dolomitization and dolomite cement in the first stage during dolomitization, and the pore setting stage in the middle and deep burial diagenetic stage. The middle and deep burial stage is the main stage of pore reduction, resulting in about 25% pore loss.