Walking type four-wheel pesticide sprayer

The utility model belongs to the technical field of pesticide spraying machines, and discloses a walking type four-wheel pesticide spraying machine which comprises a frame, a rear wheel driving assembly, a power assembly, rear wheels and a transmission device, the transmission device comprises a vertical sleeve shell, a driving chain wheel and a driven chain wheel are rotationally installed in the vertical sleeve shell, the driving chain wheel is installed on the rear wheel driving assembly, and the driven chain wheel is installed on the frame. A transmission chain is jointly wound on the driving chain wheel and the driven chain wheels, a tensioning part is arranged on the outer side of the transmission chain in a pressing mode, each rear wheel is in transmission connection with the corresponding driven chain wheel, the tensioning part comprises an installation shaft, a tensioning roller is fixedly installed on the installation shaft, the outer side of the tensioning roller is sleeved with a plastic shaft sle