With the aid of the software COMSOL Multiphysics, the analysis was made by comparing the internal stresses and strains between the two kinds of pavement concrete C30 and C40 under the coupling condition of different temperature and humidity.The results show that the internal stress generated in pavement concrete mainly concentrates on the central parts of the plate body, its sides and sharp edges when influenced by the coupling of temperature and humidity environment.In addition, pavement concrete C40 under of temperature and humidity coupling action easily produces stress concentration, the maximum of internal stress can be 12 times that of pavement concrete C30 in the same condition; while pavement concrete C30 is more likely to produce internal deformation, which can be 1114 times that of C40 in the same condition.Such phenomenon appears even more significantly under the coupling effect of big gradient in temperature and humidity.