为有效解决非饱和土中的柱形圆孔不排水收缩问题，以考虑吸力硬化的修正剑桥模型和液相方程为基础，采用未简化塑性区偏应力与纵向应力的辅助变量法，根据关联流动法则、对数大变形几何关系和平衡方程推导了柱孔塑性区关于应力分量、基质吸力和孔隙比的增量控制方程组，进而由弹塑性交界处的初值条件迭代获得了非饱和土柱孔收缩不排水解答，并开展了对比验证和解答变化讨论。研究表明：所得解答合理考虑了孔径比、吸力硬化和密实度的综合影响，对静水/纵向不等地应力场均适用，且解答退化、拓展和应用可行性得到了现有方法分析结果的多方面验证，参数物理含义明确，具有重要理论意义和良好应用前景；切向有效应力沿径向先增大后减小且在弹塑性交界处达到峰值，而基质吸力、孔隙比沿径向均先快速下降后缓慢变化；塑性区半径随着吸力硬化效应的增加而减小。

To effectively address the undrained contraction problem of a cylindrical cavity in unsaturated soils, an auxiliary variable approach without simplifying the deviatoric stress and axial stress in the plastic zone is adopted. This approach is based on the modified Cam Clay model considering suction hardening and a liquid phase equation. The incremental governing equations of the stress component, matric suction and void ratio in the cylindrical cavity plastic zone are then derived according to the associated flow rule, the logarithmic large deformation geometric relation, and the equilibrium equation. Finally, the undrained solution of cylindrical cavity contraction in unsaturated soils is iteratively achieved from the initial value condition at the elastic-plastic interface, while validations and variations of the proposed solution are discussed. The results indicate that the proposed solution has important theoretical significance and good application prospect, because it reasonably accommodates comprehensive influences of cavity radius ratio, suction hardening and compactness, yet it is applicable to both hydrostatic and longitudinal uneven in-situ stress fields, and its parameters have clear physical meanings. In addition, the degradation, extension and application feasibility of the proposed solution are verified by comparing it with analysis results of the existing methods in many aspects. The tangential effective stress increases radially first and then decreases, and it reaches a peak at the elastic-plastic interface, whereas the matric suction and void ratio decrease radially rapidly at the beginning and then change slowly. The plastic zone radius reduces with the increase the effect of suction hardening.