The invention discloses applications of human PTP4A3 gene and related drugs thereof. Applications of human PTP4A3 gene in tumor treatment, tumor diagnosis, and drug preparation are disclosed. The invention further constructs human PTP4A3 gene micromolecule interference RNA, human PTP4A3 gene interference nucleic acid construct, and human PTP4A3 gene interference slow virus, and discloses the applications thereof. The provided siRNA or nucleic acid construct containing the siRNA and slow virus can inhibit the expression of human PTP4A3 gene specifically, especially the slow virus can infect target cells efficiently and inhibit the expression of PTP4A3 gene in target cells efficiently, thus the tumor cell growth is inhibited, apoptosis of tumor cells is promoted, and thus the provided siRNA, nucleic acid construct, and slow virus have an important meaning in tumor treatment.