Proline is an important organic regulatory substance in organisms， which plays an important role in adapting marine shellfish to salinity changes. To study the effect of proline on the salt tolerance of S. constricta， high salt stress and exogenous proline were added to S. constricta. The proline content， soluble protein content and proline transporter gene expression levels of S. constricta were compared in different conditions. Under high salt stress， three free amino acids increased significantly， with the highest proline accumulation and high synthesis. Soluble protein content decreased significantly and ammonia excretion rate increased. The expressions of proline transporter SLC6A7-1 and SLC6A7-2 were significantly increased. When exogenous proline was added， the accumulation of proline content increased and reached the peak at 72 h. Soluble protein content was significantly increased， and ammonia excretion level was significantly decreased. The expression of proline transporter SLC6A7-1 increased firstly and then decreased， while SLC6A7-2 remained in a high expression state and reached its peak at 24 h. The results showed that proline could promote the synthesis of macromolecular protein and provide more energy for the salt-sensitive survival of S. constricta. It provides an important theoretical basis for further study on the regulation of proline in the salt-sensitive survival of marine molluscs.