Abstract: Based on the characteristics of some unwieldy oolitic hematite ores, tests on depth reduction-magnetic separation are carried out.The growth characteristics of metallic iron grains in depth reduction of unwieldy oolitic hematite are investigated. And the effects of different experimental conditions, such as reduction temperature, reduction time, binary basicity on the iron grains growth are discussed in detail.The results show that raising the reduction temperature and prolonging the reduction time are beneficial to the iron grains growth, while the over-high binary basicity is bad for the iron grain growth.