Abstract: The experimental studies on hydrogen isotopic deuterium from gas to liquid phase were completed by mixed ratio 1∶4 of Pt-SDB hydrophobic catalyst and hydrophillic packing. The influencing factors on number of transfer units(NTU) and transformation efficiencies of deuterium were researched. The results show that preferable NTU can be obtained by choosing suitable operational temperature and flux of exchange gas. The transformation rate increases with increasing liquid flux, but it cannot obviously be improved when liquid flux attains some level. The length of catalytic column has an obvious influence on transformation rate and 90% of transformation rate is obtained by 4 m column length at gas flux with 2 m~(3)/h, liquid flux with 1~2 kg/h and 45 ℃.