The invention relates to cassia seed lipid-lowering tea and a preparation method thereof, in particular to health food which takes plants as raw materials as well as a preparation method thereof, belonging to natural health food for people. The cassia seed lipid-lowering tea comprises the following raw materials for preparing active ingredients: cassia seed, hawthorn, kudzuvine root, semen cannabis, fructus phyllanthi and the like. The preparation method comprises the following steps: decocting for extraction; concentrating into extract; and drying and granulating. The prepared cassia seed lipid-lowering tea has the advantages of fewer raw materials for preparing the active ingredients, and reasonable and scientific raw material formula, and can really play a role of lowering lipid.