<p>Landslides, as the most frequent geological disasters, are approximated in this study as cofacial discontinuous jointed rock masses subjected to uniaxial compression conditions. Uniaxial compression tests were carried out on 5 groups of yellow sandstone samples with prefabricated cracks from dry to saturated state. The mechanical properties and failure modes of sandstones with coplanar discontinuous joints under different water content are analyzed, combining mechanical, acoustic and digital image correlation methods. The primary findings of the research are as follows: the uniaxial compressive strength of the rock masses decreases nonlinearly with increasing moisture content. The b value of the sample with high water content fluctuates more, the cracks inside the rock are more likely to develop into macroscopic cracks, and the proportion of shear signal is reduced. Based on DIC analysis, with the increase of water content, the cohesion and internal friction angle between rock particles decreases, and more tensile failure occurs in the rock failure process. This leads to easier separation of particles in the vicinity of wing cracks, which are already created in the elastic phase of the rock, and accelerates crack extension. These observations are consistent with the increase in tensile signals from acoustic emissions and the observed failure mode of the specimens. These findings can provide a theoretical reference for slope stability assessment under the background of geological engineering.</p>