In this study, sea sand was used to prepare sea sand sulfoaluminate cement concrete (SACS) by substituting river sand. Sea sand ordinary Portland cement concrete (OPCS) was used as the control group. The chloride ion solidification performance of SACS was investigated. The effects of different rust inhibitors (sodium monofluorophosphate, lithium nitrite, and triethanolamine) and their concentrations (0%, 0.5%, 1%, 1.5%, 2%, i.e., the mass ratio of rust inhibitors to sulfoaluminate cement) on rebar polarization potential and rebar corrosion in sulfoaluminate cement mortar (S_S) were studied using the methods of hardened mortar anode polarization and rebar mass loss. The results showed that after 28 days of curing, the chloride ion solidification rate of SACS was approximately 18% higher than that of OPCS. The rebar polarization potential in S_S was slightly higher than that in sea sand ordinary Portland cement mortar (OPC_S). Adding rust inhibitors to S_S shifted the rebar polarization potential in a positive direction and reduced the mass loss. The best rust inhibition effect was achieved by adding 1.5% triethanolamine, meeting the specifications for the change in rebar polarization potential, and the rebar mass loss was only 0.014 2%, approximately 91% lower than that without adding rust inhibitors.