This paper systematically studied the adsorption characteristics of C₂H₆ and C₆H₆ on aluminum nitride （AlN） and Pt modified AlN monolayers using first-principles calculations. The research results indicate that， for C₂H₆， intrinsic AlN monolayer exhibits lower adsorption energy and charge transfer amount， resulting in poor sensitivity of AlN monolayer to C₂H₆. Further research has shown that even after Pt modification， the adsorption performance of AlN monolayers for C₂H₆ has not significantly improved. Therefore， AlN is not suitable as a gas sensing material for detecting C₂H₆. In contrast， the adsorption energy of C₆H₆ on Pt modified AlN monolayer is -0.564 eV， indicating that Pt modification enhances the adsorption capacity of AlN monolayers for C₆H₆. In addition， due to changes in bandgap and work function， Pt modified AlN monolayers exhibit higher sensitivity to C₆H₆. More importantly， the moderate adsorption energy and short recovery time at room temperature （3.45×10^-4 s） indicate that Pt modified AlN monolayers have high sensitivity and good repeatability in detecting C₆H₆ molecules. The research results provide a microscopic explanation for the adsorption behavior of C₂H₆ and C₆H₆ on Pt modified AlN monolayers， promoting the further application of AlN based materials in the field of gas sensing.