In order to promote the sustainable development of coal industry,from the viewpoint of economics,the external environmental cost and recovery ratio cost for coal industry are analyzed,and an optimum recovery ratio analysis model is set up.The economic meaning of recovery ratio is analyzed,and points out that the maximal income will be acquired if the coal mining is carried out by the optimum recovery ratio in the case of the sustainable development of society,environment and resources are taken into consideration synthetically.At present,the recovery ratio of coal is far lower than the optimum recovery ratio and there is a huge space to advance in our country,so the efforts are needed to improve the recovery ratio of coal for the administrant departments of coal industry and coal mining enterprises.