The invention discloses a high-resistance starch lotus seed biscuit and a processing method thereof. Whole lotus seed flour replaces a part of low-gluten flour, the high-resistance starch lotus seed biscuit is obtained by procedures of preparation of the whole lotus seed flour, stirring, gelatinization, microwave treatment, forming, baking forming and the like, the content of resistant starch in the biscuit can reach 20%-30%, and the content of lotus seed polysaccharides can reach 0.3%-0.57%. Compared with another processing method of resistant starch biscuits, the processing method of the high-resistance starch lotus seed biscuit has the advantages that the resistant starch is not required to be processed in advance, a large amount of processing time is saved, consumption of materials is reduced, and the production cost of the resistant starch biscuit can be reduced effectively; and the processed high-resistance starch lotus seed biscuit has a complete shape, is uniform in color and is lightly golden, the surface of the biscuit is smooth, a section structure is porous, holes are fine and uniform, the biscuit tastes loose and crispy, people who eat the biscuit do not have granular sensation, the biscuit has fresh taste of lotus seeds and is nutritional, intestines problems can be prevented after people eat the biscuit for a long time, and effects of regulating blood sugar level and reducing blood fat are achieved.