Hydraulic fracturing is an important technique for enhancing the permeability of coal reservoirs and improving reservoir stimulation performance. Nanoparticle-modified Gemini viscoelastic surfactant (NPs-Gemini VES) fracturing fluid is a novel clean fracturing fluid with excellent viscoelasticity, thermal stability, and wettability, and it exhibits remarkable performance in coal reservoir stimulation. However, the mechanism by which it enhances deep coal reservoirs remains unclear, which limits its widespread application in deep coal seams. Therefore, uniaxial compression tests combined with acoustic emission (AE) monitoring were conducted to systematically investigate the effects of SGK fracturing fluid (SiO? + VES-G + KCl) on the mechanical properties and failure characteristics of coal under different treatment temperatures (25, 40, and 55 °C) and treatment durations (0.08, 0.16, 0.25, and 0.5 h). The results indicate that the SGK fracturing fluid significantly reduces the uniaxial compressive strength of coal. At all tested temperatures, the peak compressive strength exhibited an exponential decay with increasing soaking duration, characterized by a rapid initial decrease followed by a progressively slower decline. The peak strength of the coal sample treated at 55 °C for 0.5 h decreases by more than 34% compared with that of the raw coal. In addition, the action of SGK fracturing fluid makes the crack activation and expansion stage of coal sample move forward. The active stage of acoustic emission energy generally expands from the later stage of loading to the middle stage, and the cumulative energy increases in stages. When it is close to failure, it is still accompanied by the rapid release of local energy. RA–AF analysis and macroscopic crack morphologies showed that coal failure gradually transitioned from tensile-dominated failure to a composite failure mode dominated by shear cracking. This transition was more sensitive to temperature than to soaking duration, whereas prolonged soaking primarily promoted progressive damage accumulation. At 55 °C and 0.5 h, the proportion of shear-type cracking events reached 61.52%. This study systematically reveals the effects of NPs-Gemini VES fracturing fluid on the mechanical deterioration process and failure mode of coal under temperature-time coupling conditions. Important theoretical support is provided for deep coalbed methane reservoir stimulation and the optimization of permeability enhancement performance.