The present disclosure relates to an anti-miRNA delivery system, and more specifically, relates to a technique of using a cancer-targeting anti-miRNA delivery system including porous silicon nanoparticles containing anti-miRNA to which a cancer cell surface protein-binding peptide is conjugated, for use in treating cancer. As a result of intensive studies in order to use and apply anti-miR-21 oligonucleotides to the treatment of ovarian cancer, the present inventors confirmed for the first time that when porous silicon nanoparticles containing an anti-miRNA-21 oligonucleotide to which a specific cancer cell surface protein-binding peptide is conjugated are applied, apoptosis is induced in an ovarian cancer cell line and cell viability is reduced, thus, an anti-miRNA delivery system, which is the aforementioned conjugate, is expected to be usefully used as a platform for treating various cancers, especially for treating ovarian cancer.