Uniaxial tensile test and shear test were operated on wide temperature butyl isoprene rubber under -55,-40,20 and 65℃ to study the applicability of constitutive models.The ability of the constitutive model to predict other deformations was verified.On this basis,the finite element method was used to analyze errors of constitutive models and the applicability of models to butyl isoprene rubber at different temperatures and strains were determined.The results show that the higher order of constitutive model corresponds the worse prediction ability and low-order Neo-Hookean model has best prediction ability. At the same time,Yeoh model and third-order-five-term model are adopted when working temperature is between -55℃ and 20℃,and Yeoh model is chosen when the temperature is between 20℃ and 65℃ in finite element calculation of butyl isoprene rubber in flexible joint.