Optimizing the allocation of energy storage resources within wind farms can effectively mitigate the negative impacts of wind power induced strong randomness and volatility on the power system, promoting the construction of grid-friendly wind farms. Currently, wind farm energy storage systems face issues such as single application functions, low equipment utilization rates, and poor profitability, which constrain the large-scale application of energy storage systems in wind farms. To address these issues, this paper proposes a method for optimizing the capacity allocation of a multifunctional electrical-hydrogen hybrid energy storage system in wind farms, incorporating various energy storage application functions such as primary frequency regulation, power prediction compensation, and renewable energy absorption. Firstly, an operational strategy for the wind farm energy storage system is proposed, considering the three functions of primary frequency regulation, power prediction compensation, and renewable energy absorption. Furthermore, an energy management strategy for the electrical-hydrogen hybrid energy storage system, taking into account the characteristics of the energy storage equipment, is proposed. Secondly, based on this, a wind farm multifunctional hybrid energy storage system optimization allocation model is established with the goal of maximizing net revenue, using a time-series production simulation method. Finally, a case study is conducted on the optimization and allocation of a hybrid energy storage system in a wind farm in Hebei province. The research results show that the capacity allocation method under this strategy, which considers the characteristics of energy storage equipment, can meet the multi-time scale demands of the power system and effectively improve the economy of the power system.