The invention relates to a passive solid tumor-targeted anticancer prodrug andapreparation method thereof, belonging to the field of antitumor drugs. Thepreparation methodcomprises the following steps: reacting small molecular pectin with Mw of5,000 - 45,000with doxorubicin to obtain a pectin-doxorubicin conjugate with Mw of 100,000 -1,000,000,preparing the conjugate into a suspension, and treating the suspension in anultra-highpressure nano homogenizer to obtain the passive solid tumor-targetedanticancer prodrug withparticle size of 100nm - 200nm and melting point of 220-245°C, whereinthe pectin anddoxorubicin are linked by an amide bond, and the pectin is linked by an esterbond formed bycondensing carboxyl groups and hydroxyl groups of pectin molecules. Cellinhibition rate ofthe anticancer prodrug for humanized lung cancer cells NCI-H446 and A549 isequivalent tothat of doxorubicin hydrochloride. In the efficacy research of melanoma B16pulmonarymetastasis model mice, the life span of tumor-bearing mice is 42.3~2.4 days,which isremarkably higher than that of the doxorubicin hydrochloride group (23.1~10.2days).
