Planar and uniaxial tests were implemented to achieve 3nd order 5th item strain model constant of the
elastomer and it is proved this model was superior to others. In order to measure the shear modulus of the elastomer at different pressure,that biaxial device and three board sample,were designed and the shear compression test was conducted this process was simulated. The test results show that the shear modulus of the elastomer will not decrease with enhancing compression which agreed with well with the simulation.