Objective To study the antitumor effect of new photodynamic therapy (PDT) applying TMPyP4 combined with nucleolin silence on cervical cancer SiHa cells in vitro, and to explore an available combination treatment project for cervical cancer.Methods The SiHa Cells were divided into blank control group, RNAi group,PDT group and PDT-RNAi group.The proliferation activities of SiHa cells were assessed by Cell Counting Kit-8 (CCK8)assay.The apoptotic rates were measured by flow cytometry (FCM)with Annexin Ⅴ/PI staining. The invasiveness abilities were assessed by Transwell assay. Results Compared with blank control group, the inhibitory rates of growth of SiHa cells in RNAi group, PDT group and PDT-RNAi group were increased significantly (P<0.01);the inhibitory rates of growth of SiHa cells in PDT-RNAi group were higher than those in PDT group and RNAi group (P<0.05 ). The Q value was 1.27. Compared with blank control group, the apoptotic rates of SiHa cells in experiment groups were increased (P<0.05 ), and the late apoptotic rate in PDT-RNAi group was also increased;there were significant differences of the apoptotic rates between PDT-RNAi group and RNAi group, PDT group (P<0.05 ). Compared with blank control group, the cell invasiveness abilities of SiHa cells in experiment groups were decreased;there were significant differences of the invasiveness abilities of SiHa cells between PDT group and RNAi group (P<0.05).Conclusion New PDT shows a strong photodynamic effect on the SiHa cells,which can inhibit the proliferation and invasiveness and induce the apoptosis of SiHa cells invitro;nucleolin silence shows a good synergy effect to PDT.