The invention relates to polyphenol substances, a synthesis method and use thereof, in particular to flavanone derivatives, a preparation method and use thereof, which solves the problem that the prior natural flavanone compounds are difficult to extract, not easy to obtain and incapable of extensive use. The compounds have a structure (as above), wherein R1, R2 and R3 are selected from hydrogen, 1 to 8 carbonic alkyl groups, halogen, nitro group, 1 to 8 carbonic alkoxy or amino groups respectively; R4 and R5 can be selected from 1 to 8 carbonic alkyl groups, 1 to 8 alkoxy or alkenyl groups respectively; and the compounds are obtained through the reaction of compound 6-hydroxy-2,4-hydroxy acetophenone substances and aromatic aldehydes or heterocyclic aldehyde substances in polyalcohol solvent by taking high-boiling-point acid as a catalyst, and can be applied to the preparation of medicaments for resisting tumors and cardiovascular and cerebrovascular diseases. The flavanone derivatives have the activity of resisting tumors and inhibiting the cardiovascular and cerebrovascular diseases, thereby opening up a new way for preparing the medicaments and bringing new breakthroughs for the medicament field. Moreover, the synthesis method has the advantages of mild conditions and easy operation.