The molecular adsorption behavior of Zn₂SnO₄(1 1 1) crystal plane was studied. DFT theoretical simulation result shows that O₂ and H₂O molecules are adsorbed on the crystal plane by bonding with Zn atom and Sn atom respectively and forming characteristic adsorption species. H₂O molecules as characteristic adsorbed species promote the natural adsorption of O₂ molecules in the form of hydrogen bonds, N₂ molecules adsorb naturally in the form of physical adsorption. Meanwhile, the crystal surface conductivity varies with the adsorption and desorption of different gases. When the adsorbent is only O₂ molecule, the crystal surface conductivity decreases, the DOS of Fermi is from 8.00 to 4.01 electrons/eV. The conductivity of crystal surface increases when H₂O molecule acts as a characteristic adsorbent and further adsorbs O₂ molecule, the DOS of Fermi is from 5.74 to 8.51 electrons/eV. When oxygen molecules are directly adsorbed on Zn₂SnO₄(1 1 1) crystal plane, the adsorption energy is +0.79 eV, while when oxygen molecules are further adsorbed on Zn₂SnO₄(1 1 1) crystal plane through water molecule, the adsorption energy is +2.71 eV. This conclusion was confirmed by EIS. In situ Raman spectroscopy detection of acetone molecule gas sensitive experiment showed that the adsorption of O₂ molecules is slow at room temperature and fast at high temperature, which is consistent with the calculation result that O₂ molecule belongs to endothermic adsorption. The results show that, through the method of combining experiment and theory, the influencing mechanism is analyzed, which effects of different gases on adsorption properties of crystal surfaces. This work provides guidance for optimizing catalytic and gas sensitive properties of materials and realizing controllable optimization of surface properties of materials.