Abstract: Based on the difference reduction properties of rare earth oxide and iron oxide, experimental research on selective reduction of iron in NdFeB scrap using CO was carried out in a high-temperature tubular furnace. And the effect of reduction temperature, reduction time, particle size and CO flow rate on the iron reduction rate were investigated. Results showed that the reduction rate of iron in NdFeB scrap was most affected by reduction temperature and reduction time, followed by CO flow rate, and least affected by particle size. Under the conditions of particle size of 0.040 mm-0.045 mm, reduction temperature of 1 273 K, reduction time of 50 min and CO flow rate of 300 mL/min, the iron reduction degree was up to 86.23%. The reduction products were mainly composed of metallic iron, a small amount of iron element which coexisted with rare earth in the form of FeNdO₃. This will provide theoretical supports for the comprehensive recovery of rare earth and iron in NdFeB scrap.