The invention provides a single-ducted coaxial rotor/propeller saucer-shaped aircraft, which comprises an upper rotor, a lower propeller, a swashplate, a connecting rod, a spindle, a large gear, a bracket, an upper rotor wing motor, a lower propeller motor, a ducted wall, a shell, a steering engine, a support rod and a support seat, wherein the upper rotor is fixedly connected with the spindle; the spindle is supported by the bracket; the bracket is formed by connecting four support rods with one support seat; the large gear is arranged in the support seat; the support seat is connected with the spindle; the spindle is connected with the propeller motor; the ducted wall is arranged inside the shell; both ends of the support rods are respectively connected with the ducted wall and the support seat; the steering engine and the upper rotor wing motor are mounted on the upper side edge of the support seat; and the upper rotor wing motor is meshed with the large gear through a gear in the upper propeller motor. Compared with a single-thrust propeller ducted aircraft, the single-ducted coaxial rotor/propeller saucer-shaped aircraft is less in thrust loss due to no air control surface, and the rotor is combined with the propeller to provide a greater elevating force; and compared with other multi-ducted aircrafts, the single-ducted coaxial rotor/propeller saucer-shaped aircraft is simple in structure.