阐明真实地应力环境下节理岩体破坏机理对深部地下工程安全建设具有重要意义。针对含单条预制节理砂岩开展真三轴破裂试验，归纳其破坏模式，识别基本裂纹多尺度断裂特征，分析节理与应力环境对岩体破坏机理的影响。结果表明：真三向应力下节理岩体破坏模式由应力与节理共同控制；基于裂纹多尺度断裂特征，可定性判别裂纹断裂机理；最小主应力σ₃增大可显著提升剪切裂纹比重，而中间主应力σ₂增大可促进张拉型裂纹比重上升；节理的存在对于张拉断裂具有一定的促进作用，但真三向应力环境是控制岩体破坏机理的决定性因素。

Understanding the failure mechanism of cracked rock mass under the general stress state is essential for underground engineering construction safety. A series of true triaxial fracture tests on the sandstone with single pre-existing flaw were conducted. The failure modes of the cracked sandstone were analysed, and the multi-scale fracture characteristics and mechanisms of the basic types of crack were identified. Moreover, the influences of the stress state and the pre-existing flaw on the rock failure mechanism were summarized. The results indicate that the rock failure mode is controlled by the true triaxial stress and the pre-existing crack. Based on the multi-scale fracture characteristics, the fracture mechanism of the crack. The rise of minimum principal stress σ₃ can significantly reduce the percentage of the shear crack, while the rise of intermediate principal stress σ₂ conduces to the increase of the percentage of the tensile crack. The pre-existing flaw has a certain promoting effect on the initiation of the tensile crack, however, the true triaxial stress is the decisive factor controlling the rock failure mechanism.