膨润土作为高放废物深地质处置场最后一道人工屏障──缓冲层的基材，其在高压实情况下力学性能如何，对处置场的长期安全性极为关键。进行不同含水率的高压实膨润土的单轴与三轴试验，结果表明，高压实膨润土受力时存在不可恢复的塑性变形，具一定力学强度和良好的延展性。 Bentonite, as the last artificial barrier for the deep geological disposal of high-level radioactive waste, is the base material of the buffer layer. Its mechanical properties under high-pressure conditions are critical to the long-term safety of the disposal site. The uniaxial and triaxial tests of high-pressure bentonite with different water contents were carried out. The results show that there are irreversible plastic deformations in high-pressure bentonite under stress, which has a certain mechanical strength and good ductility.