In order to study the optimal low salt acclimation method of Sinonovacula contricta, the low salt semi-lethal salinity was set by 5 gradients of salinity 0, 1, 2, 3 and 5, and the low salt semi-lethal salinity was 2.005 at 96 h. With this salinity as the target salinity, three different domestication methods A, B and C were set (Group A： equal-velocity domestication； Group B： alternate domestication； Group C： gradient acclimation). The S. constricta were acclimated with low salinity from 16 to 2, and then acclimated to the target salinity for 4 days. The survival rate and submerged sludge rate of three acclimation methods were recorded. Oxygen consumption rate and ammonia emission rate of each group were detected. Superoxide dismutase (SOD) activity and Malondialdehyde (MDA) content were determined. The results showed that the survival rate (88%) and submerged mud rate (90%) of S. constricta in group C were significantly higher than those in groups A and B when acclimated to salinity 2. The oxygen consumption rate and ammonia emission rate of group C were significantly higher than those of groups A and B. Superoxide dismutase (SOD) activity reached its peak at salinity 4, and group C was significantly higher than groups A and B. Malondialdehyde (MDA) content reached its peak when acclimated to salinity 2, and was significantly lower in group C than in groups A and B. In conclusion, the low salt acclimation method of gradient acclimation (C) group is more beneficial to low salt culture of S. constricta. The results of this study provide an important reference for the development of Marine shellfish aquaculture species in China's inland low-salt waters.