The invention discloses a formation control method for unmanned helicopters. The formation control method includes inputting given lead aircraft flight instructions into state feedback output trackingmodel reference adaptive flight control systems so as to obtain control input variables for flight control mechanisms of lead aircrafts and controlling the flight control mechanisms of the lead aircrafts according to the obtained control input variables; computing relative location errors of wing aircrafts relative to the lead aircrafts according to actual flight states of the lead aircrafts andactual flight states of the wing aircrafts and inputting the relative location errors into formation keeping controllers to obtain flight instructions of the wing aircrafts; inputting the flight instructions of the wing aircrafts into the state feedback output tracking model reference adaptive flight control systems so as to obtain control input variables for flight control mechanisms of the wingaircrafts and controlling the flight control mechanisms of the wing aircrafts by the aid of the obtained control input variables. The invention further discloses a formation control system for the unmanned helicopters. The formation control method and the formation control system have the advantage that formation flight can be quickly and accurately implemented by the unmanned helicopters.