The invention discloses a processing method of sweet potato and passion fruit cakes. The method comprises the following steps: pretreatment of raw materials which are sweet potato and all parts of whole passion fruit, blending of the raw materials and auxiliary materials, and processing of the fruit cakes, wherein the pretreatment of all parts of whole passion fruit includes extraction of a fruitshell juice, separation of a fruit juice, and preparation of powdered fruit seeds; and the pretreatment of the sweet potato is preparation of mashed sweet potato. The processing of the fruit cakes iscompleted by the following steps: taking the passion fruit juice, the fruit shell juice, the mashed sweet potato and white granulated sugar, mixing and boiling the taken materials, adding Canna edulisstarch and the powdered fruit seeds, pouring the obtained mixture into a mold, molding the mixture, baking the mixture, demolding the baked mixture and packaging the demolded baked mixture. The method has the advantages of natural and simple raw and auxiliary materials, and realization of the comprehensive utilization of the whole passion fruit, and the product has the advantages of crystal clearappearance, natural, bright and rich color, richness in the passion fruit flavor and the sweet potato flavor, elastic texture, unique crispness, non-sticking to teeth, and sour and refreshing mouthfeel.