Abstract: Grid frequency security and stability are important performance indicators of the power system, and the inertia level of the power system is a key factor affecting the frequency response capability. Due to the implementation of the dual-carbon strategy in China, the proportion of new energy generation continues to increase, resulting in a continuous decline in the inertia level of the power system, which intensifies the frequency fluctuation of the power grid when it suffers from active perturbations and shrinks the system operation boundary. In order to improve the inertia situational awareness of the power system in the high-tech energy penetration scenario, enhance the frequency adaptability of the power system to active perturbations, and quantify the system operation boundary, based on the frequency response model of the power system, the frequency response process of the power grid in different time scales after being subjected to active perturbations is analyzed, and the mathematical relationship of the system frequency response is constructed. Based on the frequency response process, the minimum inertia assessment model and its solution algorithm are constructed to take into account the virtual inertia of new energy sources. Finally, based on the IEEE-39 node model, the effectiveness and accuracy of the proposed method are verified through simulation experiments.