The western coast of Bohai Bay is a typical seasonally frozen region where coastal saline soil is widely distributed. Under the influence of freeze-thaw cycles, this saline soil is prone to causing pavement distresses such as frost boiling and frost heave, thereby compromising highway serviceability. To investigate the mechanical properties of this soil, this study selected the coastal saline soil from Huanghua, Cangzhou as the research object. Subsequently, based on the Duncan-Chang model, triaxial compression tests were conducted using the LFTD1820 dynamic triaxial test system on soil specimens subjected to freeze-thaw cycles. The stress-strain relationships of the soil under different numbers of freeze-thaw cycles were analyzed, and the effect of the number of freeze-thaw cycles on the parameters of Duncan-Chang hyperbolic model was ascertained. The results indicate that the deviatoric stress-strain curves of the coastal saline soil conform to the Duncan-Chang hyperbolic model under varying numbers of freeze-thaw cycles. As the number of freeze-thaw cycles increases, the cohesion exhibits an exponential decay, while the internal friction angle generally decreases. As the number of freeze-thaw cycles increases, the Duncan–Chang parameter K decreases linearly, parameter n exhibits significant fluctuations, and the failure ratio Rf varies between 0.959–0.909. A modified Duncan-Chang model that incorporates the effects of freeze-thaw cycles is proposed, which accurately reflects the effects of confining pressure and freeze-thaw cycles on the strength and deformation of coastal saline soil.