Abstract: Environmental protection department "general industrial solid waste storage，disposal field pollution control standards" (GB18599—2001) and other 3 national pollutant control standards for the modification of the single announcement (Notice No.thirty-sixth) in 2013 show that:the location of tailing dam and the atmospheric environmental protection distance should be determined by environmental impact assessment.Because of its special nature，there is not yet a consensus in calculation on and methods of atmospheric environmental protection distance of tailings.Combining with the environmental assessment on a tailing dam，and by means of wind tunnel test，the dust source strength formula of the tailings reservoir is determined，and the calculation model of the SCREEN3 model is modified based on the characteristics of dust.Results show that ground concentration distance will be less than 1 500 meters when humidity of tailings is less than 1% and ratio of tail sand and fine sand is less than 30%，which are converted to the outside of the dam foundation to determine atmospheric environment and hygienic prevention distances.

Key words: Tailings, Dust, CREEN3 model, Atmospheric environmental protection distance