The invention relates to a gas well foam scrubbing ball and a preparation method thereof. The foam scrubbing ball is mainly composed of a spherical core body made of a foam scrubbing agent and a soluble coating with which the core body is coated, and at least one radial small hole which is communicated to the core body is formed in the coating. The preparation method comprises the steps that (1) raw materials of the foam scrubbing ball body are mixed and stirred uniformly, melted and evaporated, and the water content in the mixture is enabled to be smaller than or equal to 5%; (2) the mixture is kneaded into a paste; the pasted is squeezed into a die to obtain the spherical core body; (3) a polyvinyl alcohol solution is sprayed to the spherical core body to obtain an initial product of a foam scrubbing ball; (4) the initial product of the foam scrubbing ball is fed into drying equipment to be dried and obtain a semi-finished product of the foam scrubbing ball; (5) the surface of the semi-finished product of the foam scrubbing ball is treated, holes are formed in the foam scrubbing ball, and a finished product of the foam scrubbing ball is obtained. The foam scrubbing ball is not easy to be smashed in a falling process, can go deep into hydrops, and after the foam scrubbing ball is mixed with the hydrops, the dissolution rate can be controlled, the action time is long, and the liquid carrying efficiency is high.