The invention discloses a pesticide automatic spraying device based on a foldable spraying rod device. The device comprises a moving carrier, a spraying rod device, a liquid storage box, a main pipeline connected with the liquid storage box and a liquid pump arranged on the main pipeline, the spraying rod device comprises a first telescopic device, a second telescopic device, a middle spraying rod, a first end, a first spraying rod hinged to the middle spraying rod and a second spraying rod hinged to the middle spraying rod, one end of the first telescopic device is hinged to the middle spraying rod, the other end is hinged to the first spraying rod, one end of the second telescopic device is hinged to the middle spraying rod, and the other end is hinged to the second spraying rod; the middle spraying rod is connected with the moving carrier, multiple nozzles are fixed to the middle spraying rod, the first spraying rod and the second spraying rod, and each nozzle is connected with themain pipeline through one branch pipeline. According to the pesticide automatic spraying device, the spraying rod is foldable, the use is convenient, and the floor occupation area is small after the spraying rod is folded.