The invention discloses a eutectic of ulipristal acetate 17alpha-acetoxy-11beta-(4-N, N-dimethylaminophenyl)-19-norpregna-4, 9-diene-3, 20-dione and a preparation method thereof, as well as a pharmaceutical preparation containing the eutectic. The eutectic obtained by the invention has good stability, and is free of crystal form transformation during preparation production and storage when it is for drug use. The preparation method is simple and practicable, and is easy to realize large-scale industrialized production.