The present study aims to assess the contents of low molecular weight organic acids (LMWOAs) in the soil of artificial forests in a typical reclamation area in the Huainan mining area in China. The types and distribution characteristics of LMWOAs were discussed in the study. In addition, the relationships between LMWOAs, nutrient contents, and pH values of the soil in the study area were further analyzed in this study. (1) Nine, two, three, and five LMWOA types were detected in the reclaimed soil, coal gangue, weathered coal gangue, and farmland soil, respectively. (2) According to the clustering analysis results, the LMWOAs in the reclaimed soil were classified into two main clusters. The first cluster consisted of tartaric acid, malonic acid, acetic acid, citric acid, succinic acid, propionic acid, formic acid, and lactic acid, and the second cluster included oxalic acid. (3) The correlation analysis results demonstrated the positive effects of the LMWOA accumulation on the increase in the soil organic matter, available phosphorus, and alkali-hydrolyzed nitrogen contents. The LMWOA accumulation decreased the soil pH values. Therefore, pH values and available nutrient contents can be regulated by changing the contents of the LMWOA, further enhancing the fertility levels of reclaimed soils.