For the wider bandwidth of vibration in the engineering environment， the conventional pendulum dynamic vibration ab? sorber tends to exhibit lower efficiency due to its narrow suppression bandwidth. For this problem， this paper designs an auto-para? metric pendulum dynamic vibration absorber with a wide suppression bandwidth. The device consists of a closed coil instead of a sub-structure pendulum in the subsidiary structure and is equipped symmetrically with strong magnets on both sides of the pendu? lum. The coil oscillation cuts the magnetic induction to generate the induced current， which in turn combines vibration suppression and energy harvest. Taking the proposed dynamic vibration absorber as the object， the differential equations of motion for the non? linear vibration system are derived based on the Lagrange equations. The amplitude-frequency characteristic equations of the sys? tem are derived using the multi-scale method， and the conditions of the steady-state solutions are given by applying the Lyapunov stability theory. Using the small parameter expansion method， the amplitude-frequency characteristic equation is further simplified and the analytical expression of the suppressed frequency bandwidth of the system is found. Based on the theoretical analysis， the influence of different design parameters on the vibration suppression performance is investigated numerically. It is found that a smaller mechanical damping， spring stiffness and pendulum length， or a larger additional magnetic force can lead to a higher sup? pression performance. The above conclusions are verified by the time domain simulation. Therefore， it can be concluded that the system has improved the vibration suppression performance and can capture the vibration energy due to the introduction of magnetic force and closed coil compared to the conventional pendulum dynamic vibration absorber.