对以异丁烯、异戊二烯、二乙烯基苯为单体，以ＡｌＣｌ３、Ｈ２Ｏ为引发体系，在ＣＨ２Ｃｌ２溶剂中合成三元共聚丁基橡胶的机理进行了研究，考察了Ｈ２Ｏ和ＡｌＣｌ３用量对分子量的影响。实验结果表明Ｈ２Ｏ在该引发体系中为主引发剂，ＡｌＣｌ３为共引发剂 The mechanism of synthesizing terpolymer butyl rubber with isobutylene, isoprene, divinylbenzene as monomer, AlCl3, H2O as initiator and CH2Cl2 as solvent was investigated. The effects of the amount of H2O and AlCl3 on the molecular weight Impact. The experimental results show that H2O is the main initiator in the initiator system and AlCl3 is the co-initiator