Abstract: Nutlin-3 is a representative small molecule MDM2-p53 antagonist, which can stabilize the p53 state by disrupting the interaction between p53 and MDM2, thereby inducing the p53 signaling pathway to exert antitumor effects. In this study, six wild-type p53 tumor cell lines, HCT-116, H460, HepG2, MCF-7, A549 and SJSA-1, were used as research objects, and the effects of nutlin-3 on the proliferation of six wild-type p53 cancer cells were detected by methyl thiazolyl tetrazolium (MTT) method and plate cloning assay. The effects of nutlin-3 on H460 cell cycle and apoptosis were detected by flow cytometry. Western blot assay was used to detect ubiquitin-specific protease 7 (USP7), death domain-associated protein (DAXX), murine double minute 2 (MDM2), murine double minute 4 (MDMX/ MDM4), p53, to explore the anti-tumor mechanism of nutlin-3; co-immunoprecipitation (Co-IP) assay was used to detect the effect of nutlin-3 on the interaction between MDM2, MDMX and p53. The results showed that nutlin-3 inhibited the proliferation of H460 in a time- and concentration-dependent manner. The results of cell cycle and apoptosis showed that nutlin-3 could block the H460 cell cycle in the G0/G1 phase, and induce apoptosis by activating cleaved-PARP. Western blot results showed that nutlin-3 could up-regulate the expression of USP7, DAXX, MDM2, MDMX and p53 in H460 cells. Co-IP results showed that nutlin-3 inhibited the protein interactions between MDM2 and p53 and MDM2 and MDMX. In conclusion, nutlin-3 can significantly inhibit the proliferation of wild-type p53 cancer cells and induce cell cycle arrest and apoptosis, which may be related to the disruption of MDM2/MDMX's interaction with p53 to activate the MDM2-p53 signaling pathway.