To explore the regulation of oleuropein on the circMBOAT2/miR 106a 5p signaling pathway and further to explore its effect on the proliferation and apoptosis of oral squamous cell carcinoma cell CAL27. Methods Realtime quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of circMBOAT2 and miR-106a-5p in oral squamous cell carcinoma and adjacent tissues. Oral squamous cell carcinoma CAL27 was divided into different concentrations (0, 200, 400, 800 μg/mL) of olivopicroside group, si-NC group, si-circMBOAT2 group and 800 μg/mL+ pcDNA-circMBOAT2 group. The expression of circMBOAT2/miR-106a-5p in each group was detected by RT-qPCR, detection and validation of the correlation between circMBOAT2 and oral squamous cell carcinoma. Proliferation activity, colony forming ability and apoptosis rate of CAL27 cells were measured by CCK- 8 method, colony formation test and flow cytometry. Double luciferase assay was used to determine the targeting relationship between circMBOAT2 and miR-106a-5p. Results circMBOAT2 expression in oral squamous cell carcinoma tissue was significantly higher than that in adjacent tissues (P＜0.05), while miR-106a-5p expression was significantly lower than that in adjacent tissues (P＜0.05).Compared with the oleuropein 0 μg/mL group, the colony formation number and circMBOAT2 levels of CAL27 cells in the oleuropein (200, 400, 800 μg/mL) group were notably reduced (P＜0.05), and the inhibition rate, apoptosis rate and miR-106a-5p levels were notably increased (P＜0.05). Compared with the si-NC group, the colony formation number of CAL27 cell in the si-circMBOAT2 group was notably reduced (P＜0.05), and the inhibition rate, apoptosis rate and miR-106a-5p levels were notably increased (P＜0.05). circMBOAT2 directly and specifically bound to miR 106a 5p. Compared with the oleuropein 800 μg/mL group, the colony formation number of CAL27 cells in the oleuropein 800 μg/mL+pcDNA circMBOAT2 group was notably increased (P＜0.05), and the inhibition rate and apoptosis rate were significantly reduced (P＜0.05).Conclusion Oleuropein inhibits oral squamous cell carcinoma cells CAL27 proliferation and induce cell apoptosis by down-regulating the circMBOAT2/miR-106a-5p pathway.