高地应力隧道修建过程中软弱围岩大变形灾害问题极为突出，虽经支护能得到一定程度的治理与改善，但实际工程中支护模式的选择仍是一个难题。首先，总结当前软岩大变形隧道中常用的支护模式，即强力支护、预应力支护和让压支护，并根据支护体系承载特性的不同，将上述3种支护模式划分为主动型支护和被动型支护2类。然后，基于不同支护强度下隧道开挖后围岩变形规律，探究被动支护模式的适用性，提出以挤压因子Nc为控制指标的被动与主动支护模式选用依据，即当挤压因子Nc≥0.2时，现行的强力支护模式能够对围岩进行有效支护，而Nc＜0.2时，可根据现场围岩变形情况考虑采用主动支护模式；同时，基于锚固体系材料特性进一步分析主动支护适用性范围可知，当施加预应力不超过200 kN时可采用预应力锚杆系统，超过200 kN时则建议采用预应力锚索系统。接着，基于预应力锚索系统提出以索体延伸率εa为控制指标的主动与主动-让压支护模式选用依据，即索体工作状态延伸率εa不超过2.3%时可采用主动支护，超过2.3%时则建议采用具有更大变形能力的主动-让压支护模式。最后，依托木寨岭公路隧道典型大变形区段，基于上述支护模式的选用依据选取适宜的支护模式，并开展相应支护模式下的现场试验，试验结果一定程度上验证了选用依据的可行性。

In the process of tunnel construction under high stress, the problem of large deformation of weak surrounding rocks is severe. Although large deformation can be controlled and improved by support to a certain extent, the selection of the support type in actual engineering is difficult. Accordingly, the support types commonly used in the current soft rock tunnels with large deformation are summarized, namely, strong, prestressed, and yielding supports. According to the various bearing characteristics of a support system, these support types are classified into two: active and passive supports. Then, based on the deformation law of the surrounding rocks after tunnel excavation under various support strengths, the applicability of the passive support mode is explored. A selection method of active and passive support modes with the extrusion factor 〖WT５《TNR#I》〗N〖WT５《TNR》〗c as the control index is proposed. When 〖WT５《TNR#I》〗N〖WT５《TNR》〗c≥0.2, the current strong support mode can effectively support the surrounding rocks, and when 〖WT５《TNR#I》〗N〖WT５《TNR》〗c<0.2, the active support can be considered according to the deformation of the surrounding rocks on the site. Additionally, based on the material characteristics of the anchorage system, further analysis of the applicability range of active support shows that a prestressed anchor bolt system can be used when the applied prestress does not exceed 200 kN, whereas a prestressed anchor cable system is recommended when the applied prestress exceeds 200 kN. Based on the prestressed anchor cable system, a selection method of active and activeyielding support types with the cable elongation 〖WT５《TNR#I》〗ε〖WT５《TNR》〗a as the control index is proposed. That is, the active support can be used when 〖WT５《TNR#I》〗ε〖WT５《TNR》〗a in a working state does not exceed 2.3%, and when it exceeds 2.3%, it is suggested to adopt the activeyielding support with greater deformation capacity. Besides, relying on the typical large deformation section of the Muzhailing highway tunnel, the support types were selected based on the aforementioned basis and corresponding field tests were performed. The results somewhat verify the feasibility of the proposed selection basis.