For the surrounding rock's unstability during the soft rock tunnel excavation, especially in combination with a deep buried and long tunnel in western Hubei Province, the method of regional geo-stress field’s ?regression analysis based on in-situ measured data is employed. The digital simulation of surrounding rocks key displacement field and the comprehensive analysis of stability are both introduced. The result shows that the tunnel’s measurement regional rockmass is in high stress field, the displacement of the vault arch is relatively large and the stability of surrounding rockmass is relatively poor. The analysis result is in accord with the site phenomenon. The evaluation method applied for geo-stress field and displacement is feasible and available, which can provide some reference for the tunnel excavation.