The excavation stability takes an important role for EPB excavation in keeping surface stability and engineering safety. The prediction of EPB excavation stability based on geological data could improve the stability of the Shield. According to the data from geological prospect and field excavation, the mathematic model of the stability of Shield earth pressure balance has been analyzed, and the range of Shield thrust force has been ascertained. The nonlinear tendency of the resistance on cutting head has been confirmed by the analysis to the distribution of opening rate. The prediction standard of Shield excavation stability has been advanced in order to instruct the regulation of excavation chamber pressure and thrust force, and reduces engineering risk and cost.