The construction environment of shallow tunnel under asymmetrical pressure of the mountains in the southwest of China was analyzed from the viewpoint of geographical, topographical and geological. According to the denaturations of medium parameter and load as well as the complexity of the mechanical transmission mechanism of the lining structure, the model of stress and displacement double equivalent back analysis for getting the parameter of tunnel medium and the optimization algorithm was studied on the basis of the strength and deformation control principle of the lining structure stability, and the implementation procedures were straightened out. Then, the characteristics of the characterization parameter and unbalanced depicting index for the supporting structure of the shallow tunnel under asymmetrical pressure were refined. In the end, the mechanical response of the supporting system was studied in the finite element numerical method, and the bearing characteristics of the support structure for the shallow tunnel under asymmetrical pressure were summarized in order to provide guidance for similar engineering in design and construction control.