In order to explore the damage characteristics of mold-bag concrete under dry-wet and freeze-thaw cycles， based on the scanning electron microscope（SEM） test， the fractal dimension of the damage evolution characteristics was calculated by the box-counting methods. The fractal dimension of the pore volume was calculated by the nuclear magnetic resonance（NMR） test. The mathematical relationship was established between the porosity， permeability， and the fractal dimension. Furthermore， based on the fractal theory， using relative dynamic elastic modulus as damage index， the dry-wet and freeze-thaw damage model of concrete based on wavelet transform regression estimation can characterize the functional relationship between permeability and relative dynamic elastic modulus. It shows that the fractal dimension can be used as a damage parameter to evaluate the dry-wet and freeze-thaw resistance of concrete. The fractal dimension quantifies the microscopic characteristics of concrete and establishes the relationship between micro- and macro-damage. The results can provide a basis for the quantitative description of dry-wet and freeze-thaw damage of mold-bag concrete lining.