Molecular dynamical (MD) simulations were performed to study the structure sensitivity of H2O adsorption on adsorption different Bi2WO6 and grapheme-supported Bi2WO6 surfaces. Results show that stronger interaction happens between H2O and Bi2WO6(001) than the interactions (between H2O and Bi2WO6 (100) and between H2O and Bi2WO6 (010)), and O atom of the surface acts as the active site for H2O adsorption. The adsorption modes and locations of H2O on G-Bi2WO6 distinct with those on Bi2WO6 surfaces. The maximum adsorption amount of H2O on graphene is under 333K and 373K, with the value of 12.0403 x10(-5)mol/m(2) and 12.0538 x10(-5)mol/m(2). The maximum adsorption amount of H2O adsorption on Bi2WO6 (100), G-Bi2WO6 (100), and G-Bi2WO6 (001) is under 303K, 303K, and 333K, with 6.4079x10(-5)mol/m(2), 9.1096 x10(-5)mol/m(2), and 11.1917x10(-5)mol/m(2), respectively. Meanwhile, the maximum adsorption amount of H2O adsorption on G-Bi2WO6(010) is under 353K and 373K, with the value of 10.0452x10(-5)mol/m(2) and 10.5417x10(-5)mol/m(2). Results point out the optimal catalyst and the most appropriate pressure and temperature for H2O interacting to Bi2WO6 and grapheme-supported Bi2WO6.