Quadrotors are susceptible to periodic airflow disturbances and unstable payloads. Active disturbance rejection controller (ADRC), leveraging an extended state observer (ESO), offers an effective approach to improving disturbance rejection capability. However, due to design limitations, an ESO has limited ability to accurately estimate periodic disturbances. To address it, this paper proposes a resonant-optimized integral-enhanced ESO-based ADRC (RIADRC) for a quadrotor. The proposed method significantly improves disturbance rejection, especially in the presence of periodic disturbances. Simulation results show that, with identical control parameters, the RIADRC outperforms the ADRC, achieving superior suppression of periodic disturbances.