Elastomer is the key component of highly flexible coupling. Its structure, materials and manufacturing process determine the performance of highly flexible coupling. In this paper, Mooney-Rivlin coefficient of the material was obtained through experiment. And then static torsion characteristics of the highly flexible coupling were analyzed with ABAQUS. Results show that the highly flexible coupling with steel ring within it has better torsion performance. By using the unique design, the material and the manufacturing technology, the torsion angle of the coupling can be well controlled.