Shale gas wells in the Zhaotong block frequently have wellbore plugging problems during production, resulting in low production and efficiency, as well as production halt. To increase the success rate of gas well plugging removal, 32 different gas well blockages were studied for crystal composition. The source of blockages and the formation mechanism were next investigated by combining data from well entry materials during drilling and completion, core analysis, and dissolved oxygen monitoring. On this basis, the chemical deplugging agent HY-15 was optimized, and treatment countermeasures were developed based on various plugging characteristics. The results showed that the blockages composition is primarily iron oxides, quartz sand, barite, pyrite, and other inorganic substances. The main causes include downhole string corrosion, dissolved oxygen-pyrite interaction in the reservoir, formation proppant and mineral production. The chemical deplugging agent consists mostly of organic compound acid, organic solvents, and related additives. Blockages can dissolve up to 362 g/L in 4 h, while N80 steel sheets have a corrosion rate of not more than 0.82 g/m2 h at 80 °C. The field, together with the degree of wellbore blockage, allows for the injection of deplugging agent, deplugging agent plus foaming agent, deplugging agent plus gas lift, deplugging agent plus coiled tubing flushing, and other plug removal operations. The test wells increased output by an average of 9000 m3/d. This study can be used as a reference for wellbore plugging removal tests on shale gas wells.