Abstract: The safe and stable operation of petrochemical enterprises is the core task of production and operation, and the stability of power grid voltage is the key factor. Voltage sag can cause serious problems such as the performance degradation of electrical equipment and the instability of control systems. The governance of voltage sag is of great significance for improving the power quality of petrochemical enterprise power grid. This paper analyzes the key factors of voltage sag in petrochemical enterprises, constructs a complex power grid simulation power flow model, and carries out simulation analysis on three governance measures: replacing high-impedance transformers, FC circuit transformation, and adding new generators to catalytic units, which significantly improves the stability and reliability of petrochemical enterprise power grid operation.