This paper mainly studies the use of the activated sludge process with zeolite to upgrade the traditional secondary water treatment plants. With the addition of an appropriate amount of zeolite, the living environment of several micro-organisms in the activated sludge can be improved, thus raising the activity and number of micro-organisms and increasing the level of nitrification. Simultaneously, it also can improve size distribution and structure of sludge particles, the settling property, thus reducing the specific resistance of sludge. However, excess doses of zeolite will increase the viscosity of the sludge, which will reduce the compression performance in sludge thickening. This is not favorable to the operation of the secondary sedimentation tank and the pipeline transport of sludge. Therefore, we suggest the further study of the lower doses of zeolite, to find the optimum effect and eliminate the negative ones.