Lixivaptan crystal form I and preparation method and use thereof

The invention belongs to the field of anti heart failure drugs, and more specifically, relates to lixivaptan crystal form I and a preparation method and use of a pharmaceutical composition containing the lixivaptan crystal form I in preparation of drugs for treating hyponatremia. The lixivaptan crystal form I is prepared from 2-chloro-4-nitro benzoic acid as a starting material by esterification, hydrogenation reduction, acylation, hydrolysis, acyl chlorination and other reaction steps, and the prepared lixivaptan purity is 97.5%. The lixivaptan crystal form I and its powder are characterized by X ray diffraction diagrams, and the lixivaptan crystal form I is important for obtaining of compounds with high purity, very determined crystal form and good reproducibility due to good prospects for development and pharmaceutical value of the lixivaptan crystal form I.