Abstract: Automatic flatness control (AFC) and automatic gauge control (AGC) are interacted and coupled with each other. A novel decoupling PID control method for AFC-AGC is presented. The α-order time-delay inverse systems based on wavelet neural networks (WNN) are built and used as compensators for input/output decoupling of AFC and AGC. Then, PID controller is adopted to control the SISO systems. Theoretical analysis and numerical simulations show that the decoupling method proposed is able to decouple completely. The parameters of PID are adaptively adjustable for non-linear system with time-delay if using particle swarm optimization (PSO) algorithm. Simulation results show that the control system is simple and effective and has good performance of adaptively tracking target and resistance to disturbances. It is superior to conventional decoupling PID control to improve the accuracies of strip flatness and gauge.