The invention discloses a nozzle configuration mode of a multi-rotor wing agricultural unmanned aerial vehicle and a spraying system thereof. The nozzle configuration mode is to mount a spraying head in a rotary wing rotating area of a propeller; and the rotor wing rotating area includes a circle formed by 360-degree horizontal rotation of rotor wings during flying of the unmanned aerial vehicle and a cylinder vertically downwards radiated with the circle as the upper bottom. The spraying head is mounted in the rotor wing rotating area of the propeller; when the unmanned aerial vehicle performs the spraying operation, the propeller generates a lot of lower air currents in high-speed rotation; and medical liquor sprayed by the spraying head can effectively drop at the root parts of crops under the effect of the lower air currents, so that the pest and disease damage of the crops is effectively controlled.