The invention discloses a river chemical dosing device convenient to use for ecological treatment in the technical field of river treatment. The device comprises a ship body, a cabin at the middle ofthe outer wall of the top of the ship body, a first water pump, a second water pump, a third water pump, a driving motor, a servo motor and a motor, the right end of the water pumping pipe extends below the water surface and is provided with a filter, pipelines are arranged at the left end and the right end of the first water pump, a pipeline and a pesticide spraying pipe are arranged on the leftside and the right side of the second water pump correspondingly, the left end of the pipeline is connected with the right outer wall bottom of the mixer, and when a external thread pipe rotates, height changes, the depth of the bottom spray pipe inserted into the water surface can be changed, the pesticide spraying depth of the underwater pesticide spraying device can be adjusted, the height of the vertical water pipe can be adjusted, the height of the water surface pesticide spraying nozzle is mainly adjusted, the pesticide spraying range is changed, the water spraying pipe and the verticalwater pipe are driven by the driving piece to rotate, the spraying area is increased, and the pesticide spraying time is shortened.