Abstract: It refers for long time safety stability of foundation of buildings when buildings were constructed in subsidence area，and then space stability of subsidence area needed to be analyzed.The fundamental of foundation space stability estimated in subsidence area with additional stress analysis method was analyzed，the distribution law of additional stress of rectangle buildings was explored and provided theoretical basis for buildings sizes.According fundamental of additional stress method，and program was developed with C# language for space stability estimation and analysis，estimation and analysis of foundation spacial stability in mining subsidence area were realized with computer，it provides new ideas for estimation problems of foundation space stability in mining subsidence area，and foundation space stability estimation of mining subsidence would be more scientific，accuracy and speedy，it settles technical foundation for buildings constructed in mining subsidence.