Increasing expansion of China's coal mine production leads to the increased storage pressure in current coal silos. Most of these coals are stored in open-air coal pile. Therefore, those coal piles have caused a series of environmental pollution problems, which includes endangering workers' health and aggravating air pollution in the surrounding natural environment. Based on a single chemical dust suppressant, this paper optimizes a new type of composite binder. The Composite binder has advantages of forming the crust on surface of coal pile. The artificial wind erosion simulation method is used to test the dust solidifying characteristics of the composite binder with different physical and chemical properties and the optimal application range of the composite binder is selected. Finally, the composite binder developed is applied in an open-air coal pile and the results show that the composite binder studied in this paper has a good effect of dust solidifying. (C) 2020 Elsevier B.V. All rights reserved.