The invention discloses a compound capable of preventing and controlling plant virus disease, namely a pyridine-heterocycle-containing alpha-chalcone malonate derivative, as well as a preparation method and biological activity thereof. The pyridine-heterocycle-containing alpha-chalcone malonate derivative can be shown in a general formula (I) (described in the specification). According to the preparation method of the pyridine-heterocycle-containing alpha-chalcone malonate derivative, substituted phenylethanone, p-hydroxy benzaldehyde, absolute ethyl alcohol, sodium hydroxide, hydrochloric acid, 2-chloro-5-chloromethyl pyridine, acetone, potassium carbonate, potassium hydroxide and diethyl (dimethyl) malonate are taken as raw materials, and a target compound is synthesized by carrying out three-step reaction. The compounds a, d, o, e and w have good inhibiting effect on cucumber mosaic viruses and tobacco mosaic viruses. The general formula (I) is described in the specification.