Abstract: By means of theory analysis, the mechanical models of deformation of roadway two sides and floor heave under different coal and rock conditions are built up. The floor heave is simulated under different strength of two sides by using UDEC. The result shows that the relationship between two sides coal strength and floor heave is inverse relation. On the basis, the paper puts forward that it is useful in floor heave control with the reinforced support of coal side through the reduction of the displacement of coal side. Field research shows the technology is effective in the control of floor heave.