The status of coking coal resources and the utilization of the middlings of coking coal are analyzed in this paper, and the necessity and practicability of middlings’ rewashing is held up. Middlings of BaBao Industrial Park Coal Preparation Plant is used as sample of experiment test, through size analysis and float-and-sink test, the feasibility of middlings’ rewash is demonstrated. Two kindes of separation processes are presented : ⑴crushing-coarse and thin slime are separated separately; ⑵crushing-grinding-froth flotation. Scheme 2 is appropriate for the separation of Babao middings.Experiments confirm that the scheme 2 would be more suitable for the middlings’ separation, and the cleaned coal’s production rate of is 31.88% , the ash content is 14.4%. So there are high social benefits and economic benefits. Reclean middlings of coking coal is a new direction for the protection of coking coal resources, in the meantime, it comply with the environmental requirements and is an important measure to realize the sustainable development.