The invention provides a power grid running mode getting method based on frequency response, which aims to estimate ability of a power grid for resisting integrated power falling. The method provides a suitable power grid running mode for estimating the ability of the power grid for resisting integrated power falling. The power grid running mode getting method includes dividing regions of the power grid, getting comprehensive indexes for reflecting frequency fluctuation degrees of the various regions, classifying the regions, counting total power change quantity of units of the various regions in corresponding start modes, increasing or reducing starting frequency until the power of the power grid is balanced according to the frequency fluctuation comprehensive indexes, electric system stable restraint conditions and minimum unit running mode restraint conditions, and obtaining the running mode of the power grid. The power grid running mode getting method based on frequency response can meet electric system running restraint conditions, the frequency response of the power grid is severe increasingly when a power falling event occurs, and accordingly estimation of the ability of the power grid for resisting integrated power falling based on the basis of the running mode is more accurate.