以阳离子聚电解质为絮凝剂和硫酸铝为凝聚剂组成的复合絮凝剂，可以彻底破坏废弃钻井液的胶体体系，并使其固液分离。研究了阳离子聚电解质对废弃钻井液中悬浮颗粒表面电荷的中和作用以及对固相颗粒的絮凝方式。结果表明，大分子量的阳离子聚电解质的絮凝效果好于小分子量的絮凝效果；絮凝剂与凝聚剂加量的同步增加，可以加速固液分离，但不可过量，否则影响絮凝效率。 With cationic polyelectrolyte as flocculant and aluminum sulfate as flocculant, it can completely destroy the colloidal system of waste drilling fluid and make it solid-liquid separation. The neutralization effect of cationic polyelectrolytes on the surface charge of suspended particles in waste drilling fluid and the flocculation of solid particles were studied. The results show that the flocculation effect of large molecular weight cationic polyelectrolyte is better than the flocculation effect of small molecular weight. The flocculant and flocculant dosage increase synchronously, which can accelerate the solid-liquid separation, but not excessive, otherwise it will affect the flocculation efficiency.