Abstract: The present invention disclosed an application of an antisense oligonucleotide targeting a PBX1 promoter region G-quadruplex in a preparation of a medicine for treating melanoma. The medicine for treating melanoma has one or more of following uses: inhibiting the proliferation of melanoma cell; inhibiting the migration of melanoma cell; inhibiting the invasion of melanoma cell; inhibiting the growth of melanoma; and inhibiting the lung metastasis of melanoma. The identification of the antisense oligonucleotide targeting the PBX1 promoter region G-quadruplex provided by the present invention provides a new drug target and new treatment methods and ideas for the development of a new generation of inhibiting melanoma medicines.