Abstract: In response to the transient voltage issues at the load center of power grid with a high proportion of new energy, this paper proposes a transient voltage-frequency cascading emergency control method that involves the coordinated participation of new energy stations and energy storage. The method is characterized by the ability of new energy stations to temporarily reduce active power output to enhance dynamic reactive power support capabilities, which is of significant importance for the transient voltage security of nearby grid areas. Furthermore, the reduced active power output from the new energy stations can be compensated in a cascading manner by remote energy storage systems to avoid frequency security issues in the system. Therefore, based on transient voltage and frequency security assessment indicators, this paper establishes a two-stage optimization model with the objective of minimizing the cost of emergency control. This model optimizes the power regulation quantities for the participation of new energy stations and energy storage systems in emergency control. Finally, case studies using an improved IEEE 10-machine 39-node model demonstrate that the proposed two-stage optimization calculation can accurately and efficiently derive cascading emergency control strategies. These strategies can deeply utilize the dynamic reactive power support capabilities of new energy stations to improve the transient voltage security of the system while coordinating energy storage to ensure frequency security during transient voltage control.