Insect prevention device for seedling cultivation for citrus planting and seedling insect prevention method

The insect prevention device comprises a protective cover, a temperature control box is installed on the left side of the protective cover, an air outlet is formed in the side, close to the protective cover, of the temperature control box, and a guide assembly for killing pests is installed on the right side of the protective cover; the guide assembly comprises a fluid box, a water pump box, a cover plate, a handle, a pipeline set and a guide pipe, the cover plate is installed at the top of the fluid box, the handle is installed on the upper surface of the cover plate, the water pump box is installed at the bottom of the fluid box, the pipeline set is installed at the output end of the water pump box, and the guide pipe is installed on the outer side face of the pipeline set; meanwhile, the auxiliary pipe moves upwards along with the protection frame, so that the atomization nozzles are continuously kept horizontal with the stems and leaves of the seedlings, and then the seedlings can be maintained convenient