The paper uses the solution method to synthesis butyl rubber, the butyl rubber nature has the great important relations with the catalyst configuration,catalyst amount used and reaction time.In this paper,water (H2O) and AlEt2Cl.AlEtCl2 as the initiator. Isobutene, isoprene, hexane andmethyl chloride are taken into the three-flask in glove-box equipment,and mixed and cooled,at the cooling temperature of -80℃.Add the right amount of polymerization initiator in the polymerization system,stirring uniformly to make a full reaction,then synthesizing butyl rubber by solution method. After agitation about 40min,adding the methyl alcohol termination reaction,then product removing resolver,using the methyl alcohol to wash again,vacuum drying to constant weight under 45℃,and weighing the computation conversion rate,the determination butyl rubber molecular weight and the molecular weight distribution,using degree of unsaturation titration to measure butyl rubber degree of unsaturation,analyzing catalyst quantity to influence monomer conversion rate and molecular weight,then representing degree of unsaturation by 1H-NMR,vulcanizing butyl rubber and testing, representing its physical mechanical property.