Abstract: In order to conclude present ground in-situ stress distribution characteristics, data are gathered from active fault investigation and three drilling boreholes for in-situ stress measurement located in the north section of the Muzhailing tunnel engineering area along the Lanzhou-Chongqing railway. Combined with the high in-situ data of S_H > S_h > S_v, the core sampling of the structure features of shallow earth crust rock formation reveals that current horizontal principal stress plays a leading role in reverse fault activity. Moreover, measured maximum principal in-situ stress strikes in NE direction and reflects present compressive properties, with sinistral slip activity, of the north segment. Based on the data of crustal stress and the interrelated theories as well as criterions, it is concluded that the favorite shape of the cross-section of the tunnel are ellipses with horizontal long axis, vertical short axis and long to short axis ration as lateral pressure coefficient; when the north section of the tunnel are excavated, the hard rock has the possibility of rock burst, and the soft rock has the background of its occurrence and serious extrusion deformation. The results provide a basis for studying the characteristics of stress field in tunnel area, analyzing the stability of tunnel surrounding rock and designing engineering geological problems such as shape, structure and strength of tunnel section.