Objective To investigate the expression of the histone deacetylase SIRT7 in glioma cells and its impact on epithelial-mesenchymal transformation (EMT), as well as its effects on proliferative, migratory and invasive capabilities of glioma cells. Methods Bioinformatics analysis was conducted on data from glioma patients in the Cancer Genome Atlas (TCGA) and the Chinese glioma Genome Atlas (CGGA) databases to explore the expression of SIRT7 gene in gliomas and its correlation with tumor grading, molecular characteristics and patient clinical prognosis. Glioma cells were randomly divided into control, SIRT7 knockdown, SIRT7 overexpression, drug treatment (10 μmol/L hydrochlorothiazide) and drug (10 μmol/L hydrochlorothiazide)+SIRT7 overexpression groups. The CCK-8 assay, cell scratch assay and Transwell assay were used to observe the effects of upregulating and downregulating SIRT7 expression on glioma cell proliferation, migration and invasion. RT-qPCR and Western blotting were employed to detect the effects of SIRT7 on the expression of neural cadherin (N-cadherin), Vimentin, E-cadherin, transforming growth factor-β (TGF-β), Ki-67, and Smad3 protein in glioma cells. Nude mouse tumor-bearing experiments were conducted to observe the effect of SIRT7 knockdown on glioma growth. Results Higher expression levels of SIRT7 gene were associated with poorer clinical prognosis (P<0.0001). SIRT7 expression levels were significantly correlated with tumor grading and 1p19q coding status (P<0.01). Compared with normal HA cells, glioma cells showed significantly increased SIRT7 expression levels (P<0.01). CCK-8 assay results indicated that, compared with control group, the proliferation activity of glioma cells in SIRT7 knockout group was significantly decreased (P<0.01), while SIRT7 overexpression group showed significantly increased proliferation activity (P<0.01). EdU assay results showed that, compared with control group, the proportion of glioma cells in the proliferative stage was significantly decreased in SIRT7 knockdown group (P<0.01), and significantly increased in SIRT7 overexpression group (P<0.01). Western blotting results revealed that, compared with control group, the protein expression levels of TGF-β, Smad3, N-cadherin and Vimentin were significantly decreased in SIRT7 knockdown group (P<0.01), while the expression level of E-cadherin protein was significantly increased (P<0.05). SIRT7 overexpression group showed significantly increased protein expression levels of TGF‑β, Smad3, N-cadherin and Vimentin (P<0.05), and a significantly decrease in E-cadherin protein expression level (P<0.05). Scratch assay results indicated that, compared with control group, the migration ability of cells in SIRT7 knockdown group and drug group was significantly decreased (P<0.01), and SIRT7 overexpression group showed significantly increased cell migration ability (P<0.05). Compared with drug group, drug+SIRT7 overexpression group exhibited significantly increased cell migration ability (P<0.01). Transwell assay results showed that, compared with control group, the migration and invasion abilities of cells in SIRT7 knockdown group and drug group were significantly decreased (P<0.01), and SIRT7 overexpression group exhibited significantly increased migration and invasion abilities (P<0.01). Compared with drug group, drug+SIRT7 overexpression group showed significantly increased migration and invasion abilities (P<0.01). Nude mouse tumor-bearing assay results indicated that the volume and weight of glioma in SIRT7 knockdown group were significantly reduced compared with control group (P<0.01). Conclusions Glioma patients with high SIRT7 expression have poorer clinical prognosis. SIRT7 can regulate the TGF-β/Smad3 pathway to mediate EMT, promoting the proliferation and migration of glioma cells. SIRT7 knockdown can inhibit the growth of transplanted gliomas in nude mice.