The invention discloses a bilateral biotin-phthalocyanine zinc conjugate as well as preparation and application thereof. According to the conjugate disclosed by the invention, a biotin-cell growth-promoting factor (which is a critical micronutrient for cells to maintain normal functions, growth and reproduction) is used as a tumor target and is covalently connected onto a phthalocyanine zinc photosensitizer capable of being used for a photodynamic therapy, thus obtaining a third-generation anti-cancer photosensitizer for targeted therapy. Meanwhile, according to the conjugate, the biotin instead of a phthalocyanine zinc derivative acts a research object, human breast cancer cell MCF-7 and human embryo lung inoblast HELF act as subject cell lines respectively, a research regarding the in-vitro anti-cancer activity of the biotin is developed, and a prodrug suitable for a molecular targeted therapy is screened out, and a foundation is laid for applying the biotin instead of the phthalocyanine zinc derivative to the targeted therapy of cancers. The compound, namely the conjugate disclosed by the invention, is relatively simple in synthesis method, easily available in raw materials, low in cost, fewer in side reactions, relatively high in yield, easy to purify and beneficial for industrial production.