In order to investigate the dynamic mechanical properties of sandstone under the action of dry and wet cycles in acid-base environment, physical and dynamic mechanical tests of sandstone specimens under the coupling action of different acid-base environments (pH=3, 7, 11) and different number of dry cycles (n=0, 5, 10, 15) were conducted, and the damage performance of sandstone was further evaluated with the help of infrared thermography. It was shown that the coupling effect of acidic solution and wet and dry cycles accelerated the development of pore space in the specimens; however, the growth rate of porosity in the specimens slowed down after 15 cycles. The deterioration of peak stress and elastic modulus of sandstone was most obvious after 10 cycles of wet and dry cycles. And with the increase of the number of dry and wet cycles, the angle between the main stress surface and the rupture surface gradually increased, and the damage form of the specimen changed from brittle damage to plastic damage. Infrared thermography technology corroborated the damage occurred inside the specimen under the action of acid and alkali cycles, and the sandstone damage performance could be further evaluated according to the thermography technology. The results of the study can be used as a reference for tunneling, roadway excavation, subway and underwater construction.