This product effectively reduces drilling fluid filtration loss, especially under high temperature and pressure. It exhibits strong temperature resistance and good thermal stability. It also possesses certain abilities to inhibit clay hydration and prevent collapse, while demonstrating good resistance to salt and contamination. It can be directly applied to various water-based drilling fluid systems as a filtration loss reducer and collapse preventer, and can be used in combination with various treatment agents. (Drilling fluid compound ammonium salt)