Aiming at the problem of determining the elevation of land reclamation in mining subsidence area with high groundwater level, taking Kailuan Qianjiaying Mine as the research object, 15 groundwater level observation holes were constructed in the subsidence affected area. By analyzing the dynamic characteristics of groundwater level in Luogezhuang, Lingshang Village, Beimiao Village and Gongguang area, it is revealed that the groundwater level elevation in the study area is not affected by mining subsidence, and is mainly controlled by atmospheric precipitation and lateral recharge of surface water. On this basis, an optimization method for determining the reclamation elevation of ' the highest diving level elevation in wet season + safe superelevation ' was proposed. Taking the reclamation area of Lingshang Village ( 32.53 hm2 ) and the south reclamation area ( 10.47 hm2 ) as the engineering application object, the reclamation elevation was optimized from +22.2 m and +20.5 m to +18.2 m and +16.5 m, respectively, reducing 4.0 m, saving backfill volume and engineering cost. The optimized reclamation elevation is 0.5 ~ 2.2 m higher than the highest groundwater level elevation in the wet season, which not only avoids the damage of perennial water on cultivated land, but also significantly reduces the investment of reclamation project. It can provide technical reference for land reclamation in similar high groundwater level coal-grain compound area.