The present disclosure disclosed crystalline forms of Filgotinib hydrochloride for treating or preventing JAK-associated diseases, and preparation methods, pharmaceutical compositions, and formulations thereof. The present disclosure also disclosed the use of crystalline forms of Filgotinib hydrochloride in the prevention and/or treatment of diseases associated with JAK family. In comparison to the known crystalline forms, the crystalline forms of the present disclosure show more favorable properties in terms of formulation engineering, such as higher stability under low water activity conditions, simplicity in the preparation process and/or higher solubility.
