Disclosed are a method for preparing a benzodioxole derivative (AD-35) shown by Formula (I) and an intermediate thereof. The method of the present invention involves: using piperic acid as a raw material; and performing bromination, esterification, cyanidation, cyclopropane lactamization, amide nitrogen alkylation, deprotection, piperidine nitrogen alkylation and salification to obtain the compound of Formula (I). The method has cheap and easily available start raw materials, short synthesis routes and simple operation, and is suitable for industrial production.