In the current circumstances of receiving-end load center lacking power resource support while bearing highly centralized load，the large-capacity static synchronous compensator（STATCOM）is of great significance for increasing dynamic reactive power and improving transient voltage stability. The systematic control strategies for large-capacity STATCOM are proposed. The three control strategies，including static voltage control strategy of coordinating the fixed capacitor bank in the substation，transient voltage control strategy with nonlinear gain，and additional damping control strategy using line power as feedback，are designed. Furthermore，the optimal selection of different control functions according to voltage detection，power grid fault judgment，and shunt compensation status are discussed，and the organic coordination of various control functions is also illustrated. Digital simulation and field records verify the feasibility of the proposed systematic control strategies. The strategies proposed have been applied to?200 Mvar cascaded STATCOM in China southern power grid.