The torque sensor is a kind of testing instrument through that torque signals can be converted into electrical signals, the structural size of elastomer is an important factor affecting sensitivity of the torque sensor. On the basis of force analysis and statics analysis for elastomer, the optimal design to the elastomer was carried out by using Design Explore module in ANSYS Workbench, the reasonable optimal scheme was confirmed and the final optimal result was obtained through calculating the sensitivity of the related parameters and the response of the design variables. Under the condition of structural strength, the elastomer's strain was increased, from the aspect of structure, the sensitivity of torque sensor was improved.