When drilling into shale or high clay formations, problems such as large drilling fluid loss, well wall instability, and rock debris dispersion are faced, which seriously affect wellbore stability and drilling efficiency. At the same time, the existing water-based drilling fluid system has a rapid performance decline in high temperature environments, requires frequent adjustments, and relies on fungicides to control fermentation, resulting in increased costs. Therefore, a high-temperature stable, environmentally friendly, salt-alkali resistant, and fungicide-free filter control additive is needed to improve the comprehensive performance of the mud system and simplify the operation and maintenance process.