Because of the differences of grid network architecture, generator parameters, and load characteristics, frequency and voltage at grid nodes show certain spatial distribution characteristics when faults happen. Therefore, the same stability control measures may result in different control effects if applied at different nodes. Meanwhile, in order to improve the control effect and reduce stable control cost, the impacts of the interactions between strongly coupled factors, such as frequency, voltage, active power, reactive power and other quantities, on the effects of stability control measures need to be considered. A new optimization control strategy of under‐frequency load shedding/under‐voltage load shedding is proposed in this paper based on the load control sensitivity index. The method takes into consideration the spatial distribution characteristics of frequency and voltage, as well as the real‐time interaction characteristics of the coupled electrical quantities. Compared with the traditional load‐shedding scheme, the proposed scheme can achieve better control results. The effectiveness of the proposed method is verified through a time‐domain simulation of two actual provincial power grids. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.