Research conclusions：(1)The spatial effect on double—hole excavation is directly related to the hole diameter and the relative position。which the impact will take place when it is around twice diameters far between the face of the latter excavated cavern and the test section of the former one,and without any effect when the distance is excess the range.(2)The surface deformation is divided into three stages,which involves slow change,rapid change and gradual stability with shallow tunneling method.(3)The influence of the construction on stratum is inversely proportional to the embedded depth that with the increasing depth,the effect on the other side of stratum decreases.(4)Similarly,the inverse relation takes place between the settlement rate and the distance of test section that with the face becomes closer to the section.the rate increases.On the contrary,tlle rate constantly decreases when the distance becomes more far,which shown as an infundibulum,and the maximal value of it is at the area 2 to 4 meters after the face.(5)The transverse settlement curve of surface appears an infundibulum with wide bottom,and the settlement curve of stratum shows a standard”W”.(6)The above—mentioned conclusions offer a technical support to the protection of ground&underground key cultural relics and ancient&modern buildings in the construction of Xi’an metro.