In order to apply active dry friction dampers （DFD） to the vibration control of rotor system，a model free adaptive force control scheme is proposed，where virtual feedback tuning method is exploited to tune the initial parameters. Vibration characteristics of the active DFD-rotor system are analyzed based on a two-dimensional dry friction dynamic model. And vibration control strategies are proposed to match the response characteristics of rotors. Then，a compact-form dynamic linearization model is applied to design model free adaptive control algorithm. Meanwhile，considering the cumbersome work of initial parameter tuning，a virtual reference feedback tuning procedure is used to initialize parameters for the controller and the rules to choose parameters used for off-line data generation is also discussed herein. In order to verify the efficacy of the proposed algorithm，a rotor system containing two discs is taken as the numerical example. Results reveal that，based on one single off-line parameter tuning procedure，the rotor vibration when critical speed is traversed can be efficiently controlled by the proposed control strategy. Meanwhile，for steady vibration control，the proposed strategy is able to adaptively apply controllable forces only if the vibration level is too large，in which case the unbalanced responses of rotors can be sustained within allowable range.