In this paper, two active fault-tolerant control (AFTC) structures are proposed for multiplicative and additive actuator faults respectively. Considering that the traditional generalized internal model control (GIMC) changes the dynamic input-output relationship of the original system, more exact fault information is employed to design the robustification controller of GIMC with the help of fault diagnosis observers. Further, a feedforward compensation unit and a feedback compensation unit are respectively designed for multiplicative and additive faults, striving to approximately recover the system performance to the normal one. Finally, an air handling unit (AHU) system is provided to verify the effectiveness and superiority of the proposed structures.