Based on simulation mechanical experiments of laboratory-prepared frozen specimens of clay from deep alluvium, the behaviors of stress-strain of the frozen clay were studied, the radial unloading shear tests under different temperatures and confining pressures were done, and a linear regression model of the behavior of stress-strain was established. The testing process was as follows: Firstly, soil specimens were isotropically consolidated in high pressure state, then frozen rapidly and controlled to the test temperature quickly; secondly, in order to ensure the specimens being frozen adequately, the specimens were rested for more than 33.5 h; finally, a constant axial pressure was applied to the radial unloading specimen. The results indicate that after isotropic consolidation and frozen, the stress-strain behavior of the specimen belongs to typically viscoplastic damage type during the whole radial unloading process. The triaxial yield strength is uncorrelated with initial confining pressure, but increases linearly with temperature decreasing. The behavior of radial unloading stress-strain conforms to the revised Duncan-Chang Model.