The present disclosure discloses a sterol derivative, a preparation method therefor and a use thereof. The sterol derivative includes a sterol compound with Structural Formula (I) or a pharmaceutically acceptable salt thereof, or an extract containing the sterol compound, or a composition containing the sterol compound, wherein Structural Formula (I) is as follows: where R1 is —OH, ═O, H or C1-C3 alkyl; R2 is —OH, H or C1-C3 alkyl; R3 is —OH, ═O, H or C1-C3 alkyl; R4 is —OH, H or C1-C3 alkyl, and at least one of R1, R2, R3 and R4 is —OH. The compound with Structural Formula (I) can be used for preparing a drug having inhibitory effect on 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity and the prepared drug can effectively inhibit the HMG-CoA reductase activity or be used for preparing an anti-cancer drug.