Based on the theory of elasticity, thin plate small deflection theory and mathematical calculation, the top plate deflection equation was constructed using the Burgers body, and the relationship between the deflection and time under different boundary conditions of the mining area top plate was studied. The research results show that under the condition of four sides fixed, the maximum middle deflection is 37.77 cm, and under the condition of three sides fixed and one side free, the maximum mid-dle deflection of the free side is 46.22 cm. The calculated results of the model are roughly consistent with the field monitoring data.