Abstract: The technique of filling reclamation of mining subsidence land with Yellow River sediment has been widely applied in plain coal mine area with high groundwater level.During the filling process，a large number of external drainage will be produced，but at present the study of focusing on measurement of the drainage loss and the benefit analysis is less.Taking the mining subsidence area in the northern part of Jining as an example，the study estimated the use efficiency of drainage in three time scenarios.The water loss rate and total available water under 3 different time are estimated during sand settlement and water-adjusting process，and the utilization efficiency at drainage under different situation were calculated and analyzed.The results showed that the percentage of water loss at prompt drainage，24 h and 48 h was 3.75%，13.18% and 25.30% respectively.The potential economic benefit of drainage for supplying agricultural irrigation is about 0.64~0.82 billion yuan，for the supplement of the local water system revenue is about 1.15~1.48 billion yuan，and for industrial production is about 22.36~28.84 billion yuan.The research results indicate that the utilization of sediment and water can obtain significant economic and environmental benefits，and has a wide prospect for application.

Key words: Coal-mining subsidence, Yellow river sediment, Silting drainage, Filling reclamation, Economic efficiency assessment