The invention relates to celastrol, a celastrol derivative, a method for preparing the celastrol derivative, biogenetic salt prepared from the celastrol derivative serving as a raw material, and application of the celastrol derivative to the preparation of an antitumor medicine. The celastrol derivative has a structure shown as a formula I, wherein R1 is H, C1-C6 straight-chain or branched-chain alkyl, benzyl and benzyl with a substituent group on a benzene ring; and R2 or R3 are independent C5-C6 cyclic hydroxyl, C1-C6 chain alkyl, phenyl and substituted phenyl respectively, or R2 and R3 are cyclized with N, and the cycle is hexahydric cyclic heterocycle containing N or O. The celastrol derivative has high antitumor activity, stability and water solubility. The celastrol derivative can be salified with one of medically acceptable inorganic acids (such as hydrochloric acid, sulfuric acid and phosphoric acid) or organic acids (citric acid, cinnamic acid, succinic acid and the like); and the salt has high water solubility.