Xiaobanyu iron deposit is located in the north limb of Mount Wutai syncline, which is one of thetypical BIF-type iron deposits, in the North China Craton, the ore body is mainly hosted in the Baizhi Formation ofthe Neoarchean Wutai Group. To explore the genesis of iron ore in the deposit, three adjacent geological drillingholes area were selected as the research objects.A total of 529 iron ore samples were collected and analyzed for ironphase, in the ore bearing core sections of each drilling hole, it was found that the main iron components affecting thetotal iron (TFe) content in the samples in deposit were carbonate iron (cFe) and magnetic iron (mFe), with a correla.tion coefficient of -0.56. Compared to the surrounding deposit, the average content of carbonate iron (cFe) in the de.posit is higher. After microscopic observation, it is speculated that the original sediment of Xiaobanyu iron depositmay be mainly composed of iron carbonate (cFe), and magnetic iron (mFe) as its metamorphic product; inferred thatthe sedimentary environment of the Xiaobanyu iron deposit may be a confined or semi enclosed basin in a shallowsea and hypoxic environment. The results are beneficial for the analysis and research of the genesis of iron ore inthis deposit, and also provide reference for optimizing the mining, beneficiation, and comprehensive utilization ofiron ore for mining enterprises in this region.