The invention relates to a microfiber collagen hemostatic material and a preparation method thereof. The preparation method of the material includes the first step of sodium sulfide unhairing, the second step of shredding and fibrosis, the third step of swelling control, the fourth step of drying, the fifth step of depolymerisation and fluffing, and the sixth step of Co60 radiation sterilization, wherein in the fifth step, the obtained fasciculus is treated using a hammer mill to obtain a microfiber collagen product. According to the method, the use concentration of sodium sulphide is reduced, the efficiency of unhairing is improved, and degreasing and impure protein removal are effectively conducted; collagen materials are not oxidized and degenerated, the activity of microfiber collagen is easy to maintain, and the hemostatic effect is improved. Acid is introduced in the treating process, the degreasing and protein removal are more effective, and the adhesion property of the hemostatic material is guaranteed.