Abstract This article proposes an adaptive constrained control strategy with state constraints and uncertain parameters for an electronic throttle control (ETC) system. Compared with the current control strategies for an ETC system, state constraints and parameter uncertainties are adequately considered in the proposed control strategy. First, the nonlinear dynamic model for control of an ETC is described. Second, the asymmetric Barrier Lyapunov Function (BLF) and a backstepping control algorithm are used to ensure that the throttle opening does not exceed the constrained boundary. A parameter adaptive law is given to estimate the unknown parameter and external disturbances with an ETC system. Third, the proposed BLF controller is compared with the existing Quadratic Lyapunov Function (QLF) controller by simulation and experiment. The results show that the proposed control algorithm not only ensure fast transient performance in the control response, but also avoid the out of bounds of the throttle opening. The proposed constrained control strategy can provide excellent control performance for an ETC system.