Abstract: On the basis of elastic foundation beam，mechanics model of strip filling mining strata movement is set up，and the finite element stress analysis on filling body bearing basic roof beam is made.The research further optimized the strip filling body's layout，spacing and width，and the regression analysis on the optimization is taken.The analysis shows that: the basic roof beam bears the largest force at the supporting inner edge of filling body and has the largest deformation in central district of unfilled zone between two adjacent filling body; if the strip filling body is of advancing interval arrangement in vertical direction of working face，it can effectively enclose the gas of mined-out area，and reduce the gas concentration in the return air lane; Stability of filling body lowers with the increase of mining depth and mining height，and increased with the increase of filling body's width.

Key words: Strip filling, Strata movement, Finite element analysis, Size of filling body, Regression analysis