The invention discloses a pesticide spraying device for planting crops in mountainous and hilly areas. The pesticide spraying device comprises a carrier, a pesticide box and pesticide spraying rods, the carrier comprises a supporting plate, supporting legs arranged on the lower portion of the supporting plate and moving wheels arranged on the lower portions of the supporting legs, the pesticide box is installed on the upper portion of the supporting plate, a pesticide adding opening is formed in the pesticide box, an atomizing pump is arranged on one side of the pesticide box, a water inlet pipe of the atomizing pump is connected with the pesticide box, the pesticide spraying rods are arranged on the front side and the rear side of the supporting plate, pesticide inlet nozzles are arrangedon the pesticide spraying rods and communicated with a water outlet of the atomizing pump through hoses, a plurality of spray heads are arranged on the lower portions of the pesticide spraying rods,and two adjustable straps are arranged on one side of the supporting plate. The supporting legs are arranged on the lower portion of the carrier, the moving wheels are arranged at the bottoms of the supporting legs, a pesticide box is placed on the carrier, the straps are arranged on the supporting plate, an operator carries the straps on the back to drive the carrier to move during pesticide spraying, the pesticide box is supported by the carrier, and the labor intensity of the operator is reduced.