Abstract: With large-scale access of new energy and DC,the low transient penetration of new energy,DC commutation failures and other shocks aggravate the transient low frequency risk of the power grid. The existing frequency emergency control mode strategy based on feedforward control law is difficult to formulate,and the one-time total active power control mode adopted is easy to induce chain high-frequency risk. Firstly,based on the feedforward control theory,the existing frequency emergency control law and its influencing factors are described.On this basis,The effects of high proportion of new energy access on the existing frequency emergency control timeliness,system parameters and control objectives are analyzed. Finally,combining the advantages of feedforward and feedback control,the method of continuous frequency emergency control is developed by fusing fault event trigger and response trajectory drive. The effectiveness of the proposed control method is verified based on a typical case of actual power grid.