The invention discloses a method for improving aphid resistance of plants in the field of biotechnology. The method comprises the following steps: transferring a structure for expressing aphid gene dsRNA (double-stranded ribonucleic acid) into plants, wherein the structure for expressing the aphid gene dsRNA is double strands, a positive-sense strand and a negative-sense strand comprise an Ap forward-X-Ap reverse structure, the Ap forward part is a forward sequence or fragment of an aphid gene, the Ap reverse part is a reverse complementary sequence or fragment of the same aphid gene, and the X part is a spacer sequence between the AP forward part and the Ap reverse part; in the plants, transcribing constructed carriers and forming dsRNA in the description, in the formula, || represents hydrogen bonds formed between the Ap forward part and the Ap reverse part.