The invention discloses a transient stability emergency control strategy calculating method with generator tripping and direct-current emergency power modulation coordinated and belongs to the technical field of electric systems and automation of the electric systems. The method can gain self participation factors of a generator tripping emergency control measure and self participation factors of a direct-current emergency power modulation emergency control measure and can calculate out commutation factors of the two emergency control measures based on the expanded equal area criterion, so that coordination control indexes of the two emergency control measures can be determined. Furthermore, an iterative method is utilized to determine the final coordination emergency control measures based on the initial effective predictive control quantity. The method can be applied to calculation of an off-line security control strategy and calculation of an online pre-decision emergency control measure. Thus, the method is favorable for coordination effectiveness by using different alternating-current and direct-current measures, improves the transient stability of systems and improves economical efficiency and safety of operation of the electric systems.