Abstract: An electric control system of direct-drive permanent magnet synchronous generator based on new active disturbance rejection technology is studied. Considering the influence of the converter on the output voltage of the control system,a mathematical model of the generator set is established,and based on this,a second-order active disturbance rejection controller（ADRC）is designed. The proposed extended state observer and the convergence of the controller are analyzed,and the control parameter configuration method is given. The feasibility and control performance of the proposed control system are quantitatively analyzed by simulation. The results show that the proposed control system can control the operation process of the generator set quickly and stably,and has better dynamic performance and robust performance than the traditional vector control and first-order ADRC.