The invention relates to a preparation method of a control agent for coal dust pollution. The preparation method adopts the components with the following weight portions: 1 to 3 portions of polyvinyl alcohol (PVA), 2 to 3 portions of industrial starch, 1 to 1.5 portions of glutinous rice flour, 85 to 95 portions of water, 1 to 2 portions of polyoxyethylene nonylphenol ether and 1 to 2 portions of sodium humate. The control agent is prepared by mixing and evenly stirring the materials. The sodium humate contains 40 percent to 60 percent of humic acid and 10 percent to 20 percent of natrium. The control agent is characterized by low cost, wide material source, stable performance, wide application, innocuity and harmlessness, low corrosion rate, no odor and the like, as well as high inhibition rate, remarkable dust suppression effect, good frost resistance performance and the like. The technique that blending the control agent and spraying the control agent on the surface are combined is adopted in large-sized coal mines, ports and coal storage in China, thus realizing dust control and flame retardancy during production, storing and transporting processes of coals.