Abstract: The fracture modes of rock masses with different pore structures and varying proportions of high-strength minerals exhibit significant differences under the influence of engineering activities, which increases the complexity of underground support management. To investigate the crack evolution characteristics during the fracture process of three types of sandstone, a dual-gradient classification method was adopted based on sandstone porosity and quartz content. Uniaxial loading tests and real-time monitoring of acoustic emission throughout the failure process were conducted to analyze the evolution patterns of acoustic emission ringing counts, RA-AF values, and b-values for the three sandstone types. The experimental results indicate that: (1) With decreasing initial porosity, shear failure becomes more dominant, the fracture mode gradually changes from tensile to shear failure, and the degree of damage increases; (2) Pore structure and high-strength mineral content influence acoustic emission signals, under the combined effect of a porous medium and low elastic modulus, the transmission of elastic waves in sandstone is weakened,leading to reduced acoustic emission frequency and amplitude; (3) When the albite content exceeds that of quartz,the dislocation pile-up phenomenon generates high-frequency and dense acoustic emission signals during the compaction stage.