The invention discloses a macromolecule spray dustfall agent for mine and a preparation method and application thereof, and belongs to the technical field of dustfall agents. The dustfall agent comprises the following raw materials: 0.5-1.5wt% of acetone, 0.5-1.3 wt% of sodium sulfanilate, 0.1-0.2 wt% of sodium bicarbonate, 1-4.5 wt% of guar gum, 0.5-2.5 wt% of glycerol, 0.4-0.8 wt% of carboxymethyl cellulose, 0.3-1.3 wt% of sodium dodecyl benzene sulfonate, 0.06-0.35 wt% of fatty alcohol polyoxyethylene ether, 0.2-0.6 wt% of dodecyl dimethyl betaine and the like; the raw materials are thoroughly mixed to obtain the spray dustfall agent. The macromolecule spray dustfall agent has high water retention, moisture absorption and bonding performance, can improve the collision probability of coal dust particles and dustfall agent droplets, and can wrap coal dust for a long time, thereby being beneficial to controlling the coal dust diffusion and improving the working environment of a workingface.