Abstract: The empty area ground ’s subsidence which caused by the deep coal mining is the widespread environmental engineering geologic problem, it not only wreck the mine environment, but make great economic loss. Combining mechanical analysis and case analysis, the text make use of mathematic met hod of trigonometric function to forecast the max ground subsidence value and ground subsidence area, to predict the damage degree after the all coal seam were exploited. To adjust the mode of production and make reasonable measure to lighten ground subsidence, according to the characteristic of ground subsidence caused by deep coal mining, So that, We can provide theory sustain for lightening or preventing the harm caused by empty area ground’s subsidence.