A resistant dextrin and a method for preparing the same. In the resistant dextrin, molar content of DP1 is smaller than or equal to 1%, molar content of DP2 is smaller than or equal to 4.5%, molar content of DP3 is smaller than or equal to 7.0%, an average degree of polymerization is 6-12, a pH value is 3.0-6.0, and molar content of dietary fibers is greater than or equal to 85%. The present invention further relates to a method for preparing the resistant dextrin. Since the present invention uses starch as the raw material and divides dextrinization reaction into two stages for the first time, the degree of polymerization of the polymerization reaction is reliably guaranteed, the number of caused side reactions is decreased at the same time and the difficulty in subsequent purification treatment is greatly decreased.
