The invention provides a liquid spray method and device for small-scale water body pollution treatment. The spray method and device have the characteristics of environmental friendliness, energy saving, low cost, small size, portability, easiness in disassembling and assembling and convenience in transportation, and can be applied to garden landscape water bodies, community landscape water bodies, rivers, ponds and natural narrow water bodies which are inconvenient for the entrance and use of large-sized machines.