Hepatoblastoma (HB) was reported as the frequently diagnosed primary hepatic malignant tumor among children. No reports have shown the function of SOX7 and its relationship with the Wnt/β-catenin pathway in HB. SOX7 and factors related to Wnt/β-catenin pathway were detected using reverse transcription-quantitative polymerase chain reaction (RT-PCR) and Western blotting. MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium and flow cytometry were used to detect HB cell proliferation and apoptosis. The transwell assay uses cell invasion. In this study, RT-PCR, Western blotting, and immunohistochemistry results indicated that the expression of SOX7 was significantly reduced in HB tissues compared with adjacent noncancerous tissues, while the β-catenin was significantly increased in HB tissues compared with adjacent noncancerous tissues. There were significant differences in the PRETEXT stage and tumor metastasis between patients with low expression and high expression of SOX7. Moreover, it was found that the overexpression of SOX7 and inhibiting Wnt/β-catenin pathway significantly reduced the cell proliferation and invasion, while the cell apoptosis was significantly increased compared with the control group. This study shows that SOX7 was downexpressed in HB tumor tissues. Moreover, ex vivo experiments indicated that SOX7 was related to β-catenin and regulated the progression of HB cells.