A large number of experiments have proved that PAM works best when the pH of the wastewater is 6-8. The comparison between the two groups of sewage is alkaline sewage and the other group is acidic sewage. When the PH value is less than 6, the amount of PAM used in the treatment of sewage to achieve the same effect is significantly increased. When the pH is smaller and the acidity is stronger, the amount of use is increased until there is no flocculation effect at all, when the pH is greater than 8 At the same time, the alkaline flocculating effect is even worse until there is no flocculation effect. Through a large number of experiments, it can be concluded that anionic PAM is suitable for weakly alkaline sewage, and cationic PAM is suitable for weakly acidic sewage. Regardless of whether the sewage is strongly acidic or strongly alkaline, it affects the flocculation effect of PAM. The most ideal flocculation effect is that the sewage is neutral, so that PAM can maximize performance, improve applicable efficiency, and reduce applicable cost. Therefore, when using PAM, it is best to adjust the pH of the sewage by adding acid or alkali.