Under the background of "emission peak and carbon neutral", the dynamic reactive power support of the power grid will have a large deficit, and the adjustment coefficient can improve the dynamic reactive power support of power grid. In this paper, with the goal of maximizing the increase in bus voltage within a certain period of time after a fault, a method for optimizing the adjustment coefficient based on the ranking of transient voltage sensitivity indexes is proposed; and it is verified that this method can improve the dynamic reactive power support ability of the grid-related generators. Finally, the simulation results show that this method has a good effect on suppressing the DC commutation failure of Shanghai Power Grid and benefit to the stability of the generators and the power grid.