The invention discloses an absorbable haemostatic material of a modified starch and a preparation method thereof. The haemostatic material is etherified modified starch or a composition which is formed by one or two or more than two of the etherified modified starch, cross-linked and composite modified starch, with a molecular weight of 15,000 to 2,000,000, a grain diameter of 10-1000Mu m and a water absorbency of 1 time to 100 times. The modified starch absorbable haemostatic material has the advantages that: the haemostatic material with biocompatibility is directly applied to bloody surface of wound to stop bleeding immediately, obviously increase the water absorbency and the water absorbing speed and have more viscosity and viscidity, thereby simultaneously blocking up damaged tissues and blood vessels while stopping bleeding. The haemostatic material is easy to swell or dissolve in water and after stopping bleeding, normal saline is used for washing to eliminate the haemostatic material not participating in stopping bleeding, thus reducing residues in the body, being beneficial to wound healing, and avoiding pains caused by unclosing pledget and bandage. The haemostatic material has the physical and chemical properties of stability, difficult decomposition, long guarantee period, convenient storage, high pressure resistance, low pressure resistance, high temperature resistance, low temperature resistance and difficult change.