Combining with influent quality in summer and three loading conditions (low， medium and high)， parameter optimazition of continuous micro-filtration (CMF-S) is studied through pilot-scale test. Results show that: 1) optimal operation of CMF-S can retard membrane fouling， improve operating efficiency and reduce the costs; 2) according to operation data of the CMF-S system， the mathematical model of △TMP growth can be obtained， by which we can identify the major influencing factors， and then regulate operating parameters under different conditions to achieve operation optimization of microfiltration system.