In the present work, Raman spectra of alkane gases aqueous solution under simulated deep-sea hydrothermal environment were acquired by high temperature and high pressure deep-sea simulation experiment system. The variation laws of the Raman spectral features with various temperature and pressure were analyzed and mathematical model between them were established. The results show that for all Raman peaks of these alkane gases in aqueous solution the frequency is lower than gaseous state because of hydrogen bond; the variations of their Raman spectrum were not obvious as the pressure increased (≤40 MPa) in room temperature; and all peak positions move to lower wave number and their full width at half maximum (FWHM) increased along with changing temperature in the range of room temperature to 350 ℃ at 40 MPa pressure. The results provide an experimental basis for the in-situ detection of deep sea by Raman laser spectroscopy system in hydrothermal environment.