The invention discloses a preparation method of apixaban.The method comprises the steps that paranitroaniline serves as the raw material, paranitroaniline and delta-valerolactone are subjected to amidation ring-opening, substituting and ring-closing reactions under the action of AlMe3, and a compound 8 is obtained; the compound 8 is subjected to alpha-position dichloro substituting and condensation-elimination reactions, and a compound 7 is obtained; the compound 7 and a compound 6 are subjected to [3+2] cyclization-elimination and nitro reduction, and a compound 4 is obtained; the compound 4 sequentially reacts with delta-valerolactone and ammonium chloride under the action of AlMe3, and a compound 3 is obtained; the compound 3 is subjected to substituting and ring closing, and apixaban is obtained.According to the preparation method of apixaban, paranitroaniline and delta-valerolactone which are low in price are adopted to serve as the raw materials, operation of the whole route is simple, conditions of each reaction are mild, and the synthesizing method is easy to operate, high in yield and purity and suitable for industrial production.