The aim of the study was to investigate the characteristic function of the upregulated effects of miR-7 in methicillin-resistant Staphylococcus aureus (MRSA). After separating the MRSA in clinic, the expression of miR-7 mRNA was tested by reverse transcription polymerase chain reaction. The overexpression, inhibition of miR-7, and control group were established by plasmid in vitro. Following transfection of the bacterial strain, the effect of β-lactam antibiotics in minimum inhibitory concentration (MIC) was observed using the microporous dilution method, and antibacterial effects in vitro were observed using the dynamic growth curve method. The expression of miR-7 in sensitive MRSA was upregulated distinctly, with significant difference (P<0.05). MIC and the number of bacteria in the miR-7 overexpression group significantly increased while the inhibition group decreased prominently, with significant difference (P<0.05). The control and null plasmid groups revealed no significant difference. In conclusion, miR-7 upregulated the antimicrobial activity of MRSA, and the intervention of its expression may become a possible antibacterial target.