According to the study of thick seam mining face pressure behavior during the mining law, combined with the mining pressure and strata control relevant theory, the use of numerical simulation software UDEC Tunliu Lu'an Mine No. 3 coal seam S2201 working face simulated to obtain the corresponding under the influence of mining overburden movement law, stress contours and abutment pressure distribution characteristics. The results showed that: with the mining face similar geological conditions, compared to thick seam face pressure strength, ahead of a wider range of supporting the effects of stress, stress concentration factor of coal in front of the wall and its coal face wall distance greater . UDEC numerical simulation software through the use of coal and rock movement law of Tunliu mining coal caving under the influence of pressure regularity was important.