【Objective】To investigate the inhibitory effect and mechanism of microRNA- 30a-5p（miR-30a-5p）on epithelial mesenchymal transition in cervical cancer Hela cells.【Methods】Hela cervical cancer cell lines were transfected with miR-30a-5p mimics or negative control mimic，respectively，as 30a-5p or NC group. Control group was established with untreated Hela cervical cancer cells. miR- 30a-5p content in each group was detected by RT-PCR assay. Transwell assay was used to detect the invasion ability of the 3 groups. Western-blot assay was used to detect the expressions of N- cadherin，α- Catenin and ubiquitin specific processing peptidase 22（USP22）protein in the 3 groups. Prediction target genes of miR-30a-5p by bioinformatics methods. Antagonistic effect of USP22 over-expression on miR-30a-5p inhibition of EMT was detected by western blot assay. The relationship between miR- 30a-5p and USP22 was detected by dual luciferase assay. Subcutaneous transplantation tumor model established，and the effect of miR- 30a- 5p in vivo was observed.【Results】The miR-30a-5p intracellular quantity in 30a-5p group Hela cells was up-regulated，and the expression level of miR- 30a-5p was 853.82（862.26~843.11）times higher than that of Control group（P＜0.01）. The number of invasive cells in 30a- 5p group was 8.17（8.32~8.03），which was significantly lower than that of Control group 62.33（63.52~60.19）（P＜0.01）. USP22 may be the target gene of miR-30a-5p. In 30a-5p group，the intracellular quantity of N- cadherin protein was decreased，the intracellular quantity of α- Catenin protein was increased，and the intracellular quantity of USP22 protein was decreased. The intracellular quantity of N-cadherin protein in 30a-5p group was down-regulated，the intracellular quantity of α-Catenin protein was increased，and the intracellular quantity of USP22 protein was reduced. After USP22 over-expression，the intracellular quantity of N-cadherin protein in cervical cancer cells of 30a-5p group was up-regulated，and the intracellular quantity of α-Catenin protein were down-regulated. Dual luciferase assay showed that USP22 is a downstream target gene of miR-30a-5p（P＜0.01）. Subcutaneous transplantation tumors in 30a-5p group were significantly smaller than those in Control group.【Conclusion】miR-30a-5p may inhibit the expression of EMT related protein through the downstream target gene USP22，and the epithelial mesenchymal transition function of cervical cancer Hela cells.