To investigate the effects of sulfate on the properties of cementitious materials, mortar specimens with water-cement ratio of 0.5 and 0.35 were designed and subjected to full immersion tests to study the effects of different sulfate concentrations on the water transport properties, mechanical properties and sulfate ion transport properties of cementitious materials at different depths. The results show that the water absorption of cementitious materials after sulfate attack increases with the age of attack. The flexural and compressive strength of cementitious materials shows a trend of increasing and then decreasing with the age of sulfate attack and the concentration of attack solution. The concentration of sulfate ions increases with the increase of sulfate concentration and the concentration of sulfate ions at the same depth. The sulfate attack of cementitious materials produce swelling products to fill the internal pores and increase the mechanical properties of the specimens.