Shale gas exploration development and utilization are of importance for optimizing China's energy structure, promoting the rapid development of energy industry, improving self-sufficiency ability and level of the clean energy quality as well as reducing air pollution. By optimizing the casing program for shale gas drilling in broken formation, drilling efficiency will be greatly improved with lower drilling cost and shorter exploration cycle, so as to promote the large-scale development of shale gas resources utilization. Combined with the production practice of shale gas drilling, the discussion is made on the optimal design of casing progress for shale gas drilling in broken formation, especially in the borehole sections, borehole diamter selection, casing specifications and its running depth.