Chemical dosing device for water pollution treatment

The invention belongs to the technical field of water pollution treatment, and particularly provides a chemical dosing device for water pollution treatment, which comprises a chemical pretreatment assembly, an expansion adjustment type spraying assembly, a quantitative control type chemical storage assembly, a floating frame and a water storage tank, the agent pretreatment assembly is arranged, so that a water pollution treatment agent can be used immediately after being prepared, the agent is stirred in the circumferential direction and the horizontal direction through single power, the technical effect of uniformly and rapidly mixing the agent liquid is achieved, and cleaning is convenient; the pre-acting principle is combined with the lever principle, the arranged expansion adjusting type spraying assembly can adjust the pesticide spraying range in the transverse space and the longitudinal space, and the technical effect of adjusting and expanding the pesticide feeding coverage area in the space is achieve