The fault-tolerant formation tracking control problem for heterogeneous unmanned aerial vehicle-unmanned ground vehicle(UAV-UGV)systems under actuator faults is studied in this paper.First,since the to-pology of UAV-UGV systems is considered as directed spanning tree and only a few vehicles can receive the infor-mation of reference signals,distributed estimators which are universal for both UAV and UGV systems are designed to obtain the unknown reference signals by fully considering the apparent distinction between UAV dynam-ics and UGV dynamics.Then,based on the estimation results,universal distributed fault tolerant protocols are pro-posed for UAV-UGV systems by utilizing robust adaptive control theory.The proposed protocols can effectively compensate for the fault effects on the system performance without obtaining accurate fault information,as a result,the UAV-UGV systems are guaranteed to maintain a predesigned formation while tracking the reference signals even in the presence of actuator faults.Finally,the effectiveness of the proposed protocols is verified by the simulations.