The invention belongs to the technical field of an anticancer medicament, and provides a heterocyclic ring-containing schiff base compound with the structure of formula I, and pharmaceutically acceptable salt thereof, wherein R1, R2 and R3 are defined in specification. The invention also relates to a preparation method of the compound, and discloses a pharmaceutical composition taking the compound or the pharmaceutically acceptable salt thereof as active ingredient as well as application of the compound and the pharmaceutically acceptable salt thereof in the aspect of the anticancer medicament.