Through tests on hydration heat, electrical resistivity, pH value of pore solution, compressive and flexural strength, softening coefficient and electric flux, along with XRD and SEM-EDS analyses, the hydration process, water resistance and chloride penetration resistance of phosphogypsum slag cement concrete were studied. The results show that with the increase of CPG content, the hydration heat and electrical resistivity of cement paste at 3 days increase gradually, and the main hydration products are gypsum and AFt. When the CPG content increased from 40 % to 70 %, the 28-day compressive and flexural strength decreased by 28.3 % and 30.0 %, respectively. The pH value of the pore solution remained basically unchanged, the AFt content decreased from 27.6 % to 8.0 %, and the Ca / Si ratio of the C-S-H gel decreased from 5.44 to 3.39. The softening coefficients of phosphogypsum slag cement concrete specimens are less than 500 C, the electric fluxes are over than 1, indicating that the concrete has a very good water resistance and chloride penetration resistance.