Analyzing foundation pit engineering's stability from the point of view of deformation and displacement can avoid the complex theoretic analysis and calculation so that the stability forecast of foundation pit engineering can be quickly and effectively made.A BP network model for forecasting the ground settlement around the foundation pit and foundation pit stability was established,and an evaluation formula to calculate ground settlement was deduced.Through of case study,the BP network model and evaluation formula were also verified,and the solving condition,forecast precision and applicability of the two methods were compared.