The invention discloses coarse cereal-flavored chocolate and its preparation method. The coarse cereal-flavored chocolate is prepared from coarse cereal puffed food, a vegetable oil coating, a chocolate coating and a flavor endowing layer. The invention provides a new composition formula of coarse cereal, the vegetable oil coating, the chocolate coating and the flavor endowing layer, and high dietary fiber of coarse cereal, rich mineral matter, vitamin and functional factor of coarse cereals are fully utilized. The prepared product is rich in nutritional ingredients such as dietary fiber, minerals, high-quality vegetable protein, etc. The formula is novel, mouthfeel is unique, and nutrients are rich. The product is greatly more excellent than snack food on the market. The prepared coarse cereal-flavored chocolate is suitable for oil and young. Though content of fat in the chocolate is high, coating is thin, mass of chocolate is lower than total mass of the product by 10%, and total heat is low relative to dessert such as chocolate, etc.