Using volume translation method to improve the calculation of the accuracy of liquid density for the SRK state equation ,so has no influence on the gas -liquid balance. On the basis of SRK state equation and volume translation method and PR state equation, more accurate calculation results of the density of saturated liquid were obtained. And the results were compared with the measured data of different methods.The results show that the calculation results of saturated liquid density using volume translation method are more accurate than using the SRK state equation or PR state equation and improved the scope of the application of SRK state equation.