Abstract: In the process of drilling and completion, in order to prevent wellbore collapse or control overflow, the pressure in the wellbore is generally greater than the formation pressure, which will lead to drilling mud invasion into the reservoir and mud pollution. In view of the problem that the reservoir with high content of argillaceous sandstone is easy to be blocked by mud pollution, resulting in poor effect of new production wells and serious impact on normal production, indoor dissolution experiment of mud filter cake and rock debris is carried out. Through core flow experiment, the acid solution formula suitable for removing mud pollution and plugging in sandstone reservoir with high shale content is selected, so as to recover or improve the permeability of reservoir. The experimental results show that the fluoroborate acid system not only has good corrosion ability to drilling mud, but also has good sand stabilization performance, which can effectively reduce the excessive corrosion of acid to reservoirs.