The invention relates to a protection-dike type paper diaper and a preparation method thereof, belonging to the technical field of hygienic products. The protection-dike type paper diaper comprises a superficial layer, an absorber and a bottom film, wherein the superficial layer and the absorber are adhesive to the bottom film. The protection-dike type paper diaper is characterized in that two side edges of the absorber of the paper diaper are in the structure of a protection dike. The preparation method of the protection-dike type paper diaper comprises the preparation of the superficial layer and the absorber and the combining and cutting process of the bottom film. The preparation method is characterized in that the paper diaper is folded during preparing the paper diaper so as to form the shape of a protection dike at two side edges of the paper diaper. Dikes with absorbing function are erected at two sides of the absorber, thereby effectively stopping and absorbing a great quantity of liquid excrement, really achieving no side leakage and no back leakage, and realizing the all-around, multi-level, stereo and high-efficient protection and absorption, and really achieving safer, more reliable and more comfortable use.