The quality of sludge flocculation is directly related to the efficiency of sludge dewatering and is crucial. Many spiral wound sludge dewatering machines operate inefficiently and produce low-density sludge cakes due to improper selection of flocculants, incorrect dosages, and poor preparation of flocculant solutions, which result in inadequate flocculation and make dewatering difficult. To achieve ideal sludge flocculation, attention should be given to the following aspects: select flocculants with appropriate molecular weight, ionic strength, and ionic type based on the characteristics of different sludge types for dewatering, rather than assuming that high cost, high ionic strength, or large molecular weight flocculants are always the best. To do this, it is necessary to screen suppliers and flocculant varieties, and conduct beaker comparison tests and on-machine tests for selection. Secondly, the preparation of the flocculant solution is also very important. The flocculant should be prepared and used on the same day, and allowed to age properly after preparation; the concentration should be kept between 0.05-0.1; and the flocculant solution must be thoroughly mixed and dissolved, with no undissolved lumps or large amounts of partially dissolved swollen fish-eye particles.