Provided are a human-derived insect-resistant gene having a nucleotide sequence represented by SEQ ID NO.1, and an anti-CrylB toxin idiotype single-chain antibody encoded by said human-derived insect-resistant gene and having an amino acid sequence represented by SEQ ID NO.2. The idiotype single-chain antibody is a ²-type and has insecticidal activity, and after expression by the prokaryotic system, the primary culture thereof has binding activity to Cnaphalocrocis medinalis midgut peritrophic membrane specific receptor BBMV.
