It is difficult but significant to describe the flux variation for the membrane filtration process with complex combined filtration mechanisms. In this paper, the steady membrane frontal area (K) was proposed to improve the predictive accuracy of cake-complete model for combined fouling mechanisms of complete blocking and cake filtration. Meanwhile, the transition point when the fouling mechanisms changed from combined complete blocking and cake filtration into individual cake filtration could also be analyzed under different conditions. The results showed that the predictions of the proposed model had good agreements with experimental data under different conditions for bovine serum albumin (BSA) solution. Meanwhile, the proposed combined model possess higher accuracy (relative error (sigma) over bar =1.83%) than cake filtration ((sigma) over bar =7.36%), complete blocking ((sigma) over bar =15.90%) and pore blockage-cake ((sigma) over bar =5.54%) model. Moreover, the transition point appeared earlier at higher pressure and concentration. And larger K was obtained at higher concentration and lower pressure which represented less fouling caused by complete blocking. In addition, the application of the proposed model was validated not only by different suspensions but also by different membranes.