<p>To improve the dynamic performance of three-level buck converters with constant power loads due to strong coupling and negative impedance characteristics, a composite inverse decoupling control strategy is proposed. A nonlinear state space mathematical model of the converter is established, and the inverse system theory is used to verify the reversibility of the model. By constructing an inverse system, the original model is decoupled into a first-order and a second-order pseudo-linear subsystems. Then, a composite control strategy is proposed based on the two-degree-of-freedom internal model control method and state feedback control method. Controllers are designed for these pseudo-linear subsystems, and the selection method of the control parameters is discussed. Simulation and experimental comparisons with linear decoupling PI control and sliding mode control show that the proposed control strategy has a faster dynamic response and stronger anti-interference capability.</p>