Land subsidence in coal mine would change the type of soil, which may be the result of the change of dissolved organic matter (DOM) characterization in surface land soil. When the subsidence wetland is formed, the 3DEEMs results show that when the subsidence wetland is formed, the protein-like materials decrease and the humic acid materials increase. The UV absorption results imply that the structure of DOM become more complex and the degree of humification of DOM increases. The correlation analysis indicates that changes have significant influence on the bioavailability of metals.