An unmanned aerial vehicle comprising a multi-rotor structure, wherein the unmanned aerial vehicle comprises a fuselage, at least four first rotors, second rotors the number of which is same as that of the first rotors, and rotor arms the number of which is same as that of the first rotors or the second rotors, each rotor arm being provided with a first rotor and a second rotor; the multi-rotor structure comprises: first rotary connecting pieces the number of which is same as that of the first rotors, wherein one of the first rotors is rotationally connected with one of the rotor arms through one of the first rotary connecting pieces, and the first rotary connecting piece comprises: a first motor, wherein the first motor comprises a first surface and a second surface, and the first motor is fixed on the rotor arm through the second surface; a first dismounting thread group, wherein the first rotor is rotationally connected with the first surface through the first dismounting thread group to achieve the mounting or dismounting between the first rotor and the first motor just by rotating the first rotor; and second rotary connecting pieces the number of which is same as that of the second rotors, wherein one of the second rotors is rotationally connected with one of the rotor arms through one of the second rotary connecting pieces, and the second rotary connecting piece comprises: a second motor, wherein the second motor comprises a third surface and a fourth surface, and the second motor is fixed on the rotor arm through the fourth surface; and a second dismounting thread group, wherein the second rotor is rotationally connected with the third surface through the second dismounting thread group to achieve the mounting or dismounting between the second rotor and the second motor just by rotating the second rotor. first rotary connecting pieces the number of which is same as that of the first rotors, wherein one of the first rotors is rotationally connected with one of the rotor arms through one of the first rotary connecting pieces, and the first rotary connecting piece comprises: a first motor, wherein the first motor comprises a first surface and a second surface, and the first motor is fixed on the rotor arm through the second surface; a first dismounting thread group, wherein the first rotor is rotationally connected with the first surface through the first dismounting thread group to achieve the mounting or dismounting between the first rotor and the first motor just by rotating the first rotor; and second rotary connecting pieces the number of which is same as that of the second rotors, wherein one of the second rotors is rotationally connected with one of the rotor arms through one of the second rotary connecting pieces, and the second rotary connecting piece comprises: a second motor, wherein the second motor comprises a third surface and a fourth surface, and the second motor is fixed on the rotor arm through the fourth surface; and a second dismounting thread group, wherein the second rotor is rotationally connected with the third surface through the second dismounting thread group to achieve the mounting or dismounting between the second rotor and the second motor just by rotating the second rotor.