In order to explore the damage law of freeze-thaw effect on the physical and mechanical properties of limestone, uniaxial compression tests were carried out on Basu limestone with 0,20,40,60 and 80 freeze-thaw cycles. The effects of freeze-thaw deterioration on the macroscopic physical and mechanical parameters and failure modes of rock were analyzed, and the energy evolution law of freeze-thaw damage samples under uniaxial compression was explored. Secondly, considering the coupling effect of freeze-thaw and load, based on the assumption of generalized Lemaitre strain equivalence, a piecewise damage constitutive model of freeze-thaw limestone with Weibull distribution was established. The results show that the mass, elastic modulus and compressive strength of limestone decrease with the increase of freeze-thaw cycles, and the failure mode changes from a single tensile failure to a combination of tensile and shear failure. The failure samples of 60 times and 80 times of freeze-thaw cycles show obvious bulging effect, indicating that freeze-thaw action causes ductile failure of limestone. Under the condition of uniaxial compression, the theoretical model curve is basically consistent with the experimental data curve in the pre-peak section. The non-compaction section parameter m is an important index of rock plasticity. The non-compaction section parameter m is reduced from 39.8 to 4.32, which is reduced by 89.15%. The model reveals the transformation of limestone from brittleness to ductility. The research results provide theoretical support for the related problems of seasonal geotechnical engineering.