A crystal form of androgen receptor inhibitor and its preparation method are provided.Specifically,Provided (S)‑4‑(3‑(4‑(2,3‑dihydroxypropoxy)phenyl)‑4,4‑dimethyl‑5‑carbonyl‑2‑thioimidazoline‑1‑yl)‑2‑(trifluoromethyl)benzonitrile (a compound of formula (I)) and its preparation method,The method comprises the following steps: 1) adding any crystal form or amorphous compound shown in formula (I) into an appropriate amount of organic solvent,Cooling crystallization after heating and dissolving,The organic solvent is selected from esters with carbon atom number less than or equal to 5KetonesNitrilesAny of various ethers or their mixed solvents；2) Filter crystallization and wash,Dry.The type I crystal of the compound of formula (I) has good chemical stability and crystal stability, and the crystal solvent used is low toxicity and low residue, so it can be better used in clinical treatment.提供了一種雄性激素受體抑制劑的結晶形式及其製備方法。具體地，提供了(S)‑4‑(3‑(4‑(2，3‑二羥基丙氧基)苯基)‑4，4‑二甲基‑5‑羰基‑2‑硫代咪唑啉‑1‑基)‑2‑(三氟甲基)苯甲腈(式(I)化合物)的I型結晶及其製備方法，所述方法包括：1)將任意晶型或無定型的式(I)所示化合物加入適量的有機溶劑中，加熱溶清後冷卻析晶，所述有機溶劑選自碳原子數小於等於5的酯類、酮類、腈類、醚類的任意一種或它們的混合溶劑；2)過濾結晶並洗滌，乾燥。所得式(I)化合物的I型結晶具備良好的化學穩定性和晶型穩定性，並且所用結晶溶劑低毒低殘留，可更好地用於臨床治療。
