The present invention provides a power grid source steady state voltage regulating optimization method for improving the transient voltage support capability of a power grid. The method comprises the steps of (1) establishing a steady state model and a transient model for the simulation and calculation of the power grid; (2) evaluating the transient voltage recovery characteristic of the power grid; (3) collecting the data of a generator and a static compensation capacitor; (4) determining the adjustment trend for enhancing the transient reactive supporting capability of the power grid; (5) making a steady state voltage regulating scheme corresponding to different power grid source steady state reactive outputs; (6) determining a steady state voltage regulating preferable scheme of the generator and the static compensation capacitor. The power grid source steady state voltage regulating optimization method for improving the transient voltage support capability of the power grid provided by the present invention can fully utilize the transient reactive output capability of a generator set to improve the transient voltage recovery characteristic of the power grid and improve the safe and stable running level of the power grid on the basis of satisfying the steady state voltage regulation.