The invention discloses a multi-rotor aircraft, which comprises a craft body, a landing gear, propellers (primary and auxiliary propellers), a motor, an electronic speed controller, a battery and a fly control system, wherein the craft body is composed of a fuel engine, a synchronous gear driving mechanism, a rack and multiple motor support arms; the propellers comprise a pair of primary propellers and multiple pairs of auxiliary propellers; the primary propellers are coaxial and rotate at the same speed in opposite directions; the primary propellers are driven through the synchronous gear driving mechanism by the fuel engine and are used for bearing primary lifting force of an aircraft body; each primary propeller is provided with two rotors; the auxiliary propellers are driven by the motor and used for controlling altitude balance, suspension, lifting and maneuver flight in front, back, left and right directions of the aircraft; the auxiliary propellers are also used for bearing small part of the lifting force. According to the multi-rotor aircraft, the disadvantages of electric power and fuel power are improved; the advantages of the electric power and the fuel power are perfectly combined; through oil-electricity hybrid power, the load capacity and the duration of the multi-rotor aircraft are improved to a great extent.