<p>Permanent magnet synchronous motors (PMSMs) are widely used in the joints of high-precision robotic arms. However, their performance can be easily affected by multisource disturbances, which may lead to fluctuations in motor output speed. To address this issue, this study proposes a strategy that utilizes composite quasi-resonant active disturbance rejection control to suppress speed fluctuations in PMSMs. First, multisource disturbance sources are categorized into equivalent torque disturbance and equivalent load disturbance. Two types of disturbance models are established, and a dynamic model containing multisource disturbances is constructed, from which the active disturbance rejection control (ADRC) state equations are derived. Next, the ability of ADRC to suppress multisource disturbances is analyzed. Subsequently, by integrating the hyperbolic tangent function with the resonant controller, the traditional quasi-resonant controller is enhanced. This newly designed resonant controller is then embedded into the ADRC controller to improve its ability to suppress multisource disturbances, and the stability of this controller is analyzed. Finally, a PMSM drive system is developed to validate the effectiveness of the proposed method empirically.</p>