The present invention relates to methods of overcoming the resistance to an EGFR (Epidermal Growth Factor Receptor)-targeting antibody through a peptide that binds specifically to neuropilin-1 (NRP1). Moreover, the present invention relates to a fusion antibody in which a peptide that binds specifically to NRP1 is fused to an EGFR-targeting antibody, and to a composition of overcoming the resistance to an EGFR-targeting antibody alone by co-administration of the EGFR-targeting antibody and an NRP1-binding peptide-fused Fc. In addition, the fusion antibody according to the present invention, in which the NRP1-specific binding peptide is fused to an EGFR-targeting antibody, overcomes the resistance to the EGFR-targeting antibody alone in pancreatic cancer. Furthermore, the fusion antibody, in which the NRP1-specific binding peptide is fused to the EGFR-targeting antibody, also overcomes resistance to the EGFR-targeting antibody alone even in lung cancer. Thus, the NRP1-specific binding-fused EGFR-targeting antibody according to the present invention may be highly effective in the treatment of various tumors resistant to EGFR-targeting antibody alone.