In the context of general education reform, quality management in lower secondary schools requires a systematic and continuous improvement-oriented approach. This paper clarifies the theoretical foundations of educational quality management based on the PDCA (Plan-Do-Check-Act) cycle, while analyzing key management contents and the factors influencing its application in schools. The study employs methods of literature analysis, synthesis, and generalization to systematize theoretical perspectives and identify research gaps in the context of lower secondary education. The findings indicate that the PDCA cycle provides a closed-loop management framework that supports the organization of educational activities in a planned, controlled, and continuously improved manner based on evidence. The application of PDCA contributes to enhancing the effectiveness of quality management and fostering a culture of continuous improvement within schools; however, it is influenced by factors such as policies, socio-economic context, managerial capacity, and staff quality. The research findings provide useful references for the application of PDCA in quality management in lower secondary schools.