Abstract: The excessive application of fertilizers for a long time has led to the decrease of soil productivity in rice fields and the increase of the proportion of middle-and low-yield fields, which has seriously threatened the food security. In recent years, the effect of green replacement technology of rice fertilizer on soil nutrient conversion has become a research hotspot. However, at present, the influence factors and mechanism of soil organic carbon conversion after continuous return to the field of Astragalus sinicus green manure under the treatment of reduced fertilization were still lacking. Therefore, the process of soil organic carbon conversion after continuous return to the field of Astragalus sinicus under the treatment of reduced fertilization was reviewed, and then the effects of soil physical, chemical and biological properties on organic carbon conversion and its mechanism after continuous return to the field of Astragalus sinicus were analyzed. In particular, the role of microbial species related to carbon fixation in the organic carbon conversion was described, which provided a new way for effective regulation of organic carbon conversion in paddy soil in the future, so as to realize soil carbon increase and rice yield increase.