Abstract: For a class of nonlinear switched systems subject to multiple constraints including input saturation, parametric uncertainties, and unmeasurable states, we propose a robust control strategy for input-saturated switched systems based on the fully actuated system approach. The main advantage of this method is its ability to cancel out inherent nonlinearities, which ensures that the closed-loop dynamics exhibit linear time-invariant characteristics with freely assignable eigenvalue poles and simplifies the controller design process. Firstly, a fully actuated system model is established for the input-saturated switched system. Secondly, an extended state observer is designed to simultaneously estimate the unmeasurable states and nonlinear terms, while the convex hull approach is employed to handle the input saturation. For each subsystem, a controller is designed using the fully actuated system method, with its parameters determined through parametric design and linear matrix inequality (LMI) solutions. Finally, by leveraging the construction of multiple Lyapunov functions, linear matrix inequalities and the average dwell time strategy, the stability conditions for the closed-loop switched system are derived and established. Furthermore, numerical simulations verify the effectiveness of the proposed control scheme.