Multi-rotor aircraft

The invention discloses a multi-rotor aircraft, which includes an undercarriage, a power apparatus, a transmission apparatus, a variable pitch apparatus, a mounting frame, and four groups of propellers. Each group of the propeller includes two paddles and a central shaft, wherein the paddles are hinged to the central shaft movably. A belt wheel is arranged on the central shaft. The mounting frame is fixedly arranged above the undercarriage. The power apparatus is fixedly arranged on the mounting frame and includes a motor, a reduction gear and a one-direction bearing. The propellers has the function of variable pitch so that pushing force can be changed quickly in intensity and direction, thus achieving aerobatic flight. Synchronous belt torsion can change the rotational direction of the propellers with simple and high-effective transmission, and also a buffer effect when the propellers impact an obstacle is achieved, thereby protecting the propellers and the gear. When the aircraft is descended quickly, the