Steering command synthesis is very important for modern fly-by-wire flight control system aircraft,especially the linkage steering mode of dual-pilot brings great complexity to control command synthesis. Based on the role of the pilot and the fault mode of the steering,this paper analyzes the command synthesis concept of the steering,designs the command synthesis logic algorithm,and studies the design consideration of the control command shaping. The simulation results show that this method successfully realizes the correct selection of the command under the conditions of the normal,sensor fault and one-sided mechanical stuck fault of the dual-pilot linkage steering,and solves the problem of high safety command synthesis of the complex steering of the fly-by-wire control system,which has good engineering application value.