By adjusting process variables such as the content of rGO (0.1, 0.5, and 1 g), hydrothermal temperature (150, 170, and 190 °C), and hydrothermal duration (5, 10, and 15 h), gas sensors based on V₂O₅/rGO nanohybrid composites were created. The prepared V₂O₅/rGO nanohybrid composites, particularly the flower-like structures, demonstrated favorable characteristics for gas sensing systems. At ambient temperature (30 °C) to 350 °C, the V₂O₅/rGO nanocomposites sensors' ethanol gas detection capabilities were simulated over ethanol vapor. The prepared V₂O₅/rGO nanocomposites were characterized by PXRD, FESEM, and EDAX. The surface morphology was confirmed by SEM, the crystal structure of V₂O₅/rGO nanocomposites, peak intensity, and lattice constants was confirmed by PXRD, and the presence of vanadium, oxygen, and carbon elements in the nanocomposites was confirmed by EDAX. The COMSOL Multiphysics 5.5 simulation was conducted for a better understanding of the sensing mechanism. The V₂O₅/rGO nanocomposite sensor, which resembled a flower, demonstrated flawless reversibility and quick response-recovery qualities to ethanol gas at two operating temperatures. The research's results have implications in the building of intelligent materials that can detect ethanol fumes for the chemical and food industries.