To address the issues of poor frequency regulation performance and torsional oscillations in traditional wind farm primary frequency regulation algorithms, this paper proposes a coordinated control algorithm for wind power primary frequency regulation considering dynamic classification of unit spinning reserves. First, according to the safe speed operation requirements, power regulation capability, and releasable rotating energy storage capacity, the wind turbines in the wind farm are divided into four categories, namely, priority spinning reserve units, general spinning reserve units, weak spinning reserve units, and non-spinning reserve units. Second, the primary frequency regulation capability of the priority spinning reserve units under different power limit conditions is obtained. For these priority units, a wind farm primary frequency regulation control algorithm based on frequency regulation capability is adopted. Finally, the proposed algorithm is verified on a simulation platform. The experimental results show that the proposed algorithm can meet the primary frequency regulation requirements of the power grid, achieving better frequency regulation performance than traditional algorithms, and significantly reduce shaft oscillations in the wind turbine units.