The main component of solid acid is acid ester, which has no acidity in solid state. and forms the corresponding carboxylic acid after dissolution in water, which can dissolve formation rocks. In the aqueous solution, when reaching a certain temperature, the solid acid undergoes a chemical reaction to form an organic/inorganic acid, which produces physical and chemical effects on special blockages in the reservoir, and finally transforms into "soluble complexes" to achieve the purpose of reservoir reconstruction and plugging removal.