Disclosed in the present invention are a 6,8-substituted naringenin derivative as shown in formula (I): in which A 6 and A 8 in formula (I) are respectively selected from H, halogen, hydroxyl, an alkyl group with 1-3 carbon atoms, and a straight-chain alkenyl, alcohol group, aldehyde group, or carboxylic acid group containing 2-3 carbon atoms, obtained by modifying naringenin as lead compound, or a pharmaceutically acceptable salt thereof, a preparation method therefor and use thereof in preparation of drugs for improving the function of the respiratory system and relieving cough.