<p>The combined effects of hygrothermal environment and salt weathering have become one of the primary drivers of rock weathering and the triggering of geological hazards. Rock weathering is substantially accelerated in a hygrothermal-salt coupled environment due to salt crystallization and the thermal expansion of minerals. It is crucial to examine the deterioration process and damage mechanism of rocks in hygrothermal-salt coupled environment. In this paper, a hygrothermal cycle test was conducted on the sandstone obtained from Tongchuan City, Shaanxi Province, to examine the evolution law of damage and deterioration of sandstone when subjected to different cycle number and Na₂SO₄ solution concentrations. By combining the real-time thermoacoustic emission (TAE) with nuclear magnetic resonance (NMR), enabling the dynamic tracking of the damage process and pore structure changes. The results demonstrate that, following the hygrothermal cycle, the mass of sandstone initially increases and then decreases. The higher the concentration of Na₂SO₄ solution, the more severe the mass loss. As the concentration of salt solution increases, more salt crystals form within the rock, filling the pore structure. Consequently, the pore changes measured by NMR are mainly dependent on the decrease in micropores and the increase in mesoporous pores. The Na₂SO₄ solution accelerates the weathering damage in sandstone, increases the AE activities and dispersion of the <i>b</i> value. As a consequence of the salt crystallization pressure and the non-uniform thermal expansion stress of the mineral, the small-scale failure develops into a large-scale macro-failure, resulting in the weathering and disintegration of the rock.</p>