Abstract: In response to the substantial challenges introduced by the large-scale integration of wind power into new power system, hybrid energy storage technology is involved in wind farm grid-connected smooth output power and auxiliary primary frequency regulation to effectively slow down the output power fluctuation of wind farm and actively support grid frequency security. Taking into account the advantages of different energy storage systems, this paper proposes a hybrid energy storage stabilization-frequency modulation scheme based on flywheel and lithium battery. Considering the full life cycle cost of the hybrid energy storage system, combined with the needs of multiple time scales, a hierarchical model of capacity optimization configuration is constructed. The smoothing layer considers electricity sales revenue and carbon trading revenue, the frequency modulation layer considers primary frequency modulation revenue, and fully considers the coupling characteristics between the hierarchical models, as well as takes the maximum annualized revenue as the goal. The calculation and analysis are carried out through actual data. The results show that compared with hybrid energy storage, which only participates in smoothing fluctuations, the hierarchical capacity allocation model considering wind power consumption and primary frequency modulation demand can effectively give full play to their respective advantages in power smoothing and frequency modulation support. The overall economy is better, and the net income of the whole life cycle of the wind-storage combined system is effectively improved.