The invention discloses a nano iron powder sintering body containing a nano ferroferric oxide and a preparation method of the nano iron powder sintering body. The nano iron powder sintering body is prepared from the following raw materials by mass percentage: 80%-100% of nano ferroferric oxide powder and 0-20% of additive powder, wherein the additive powder is the powder containing one of C, Al, Si, Mn, Sn, Ni, Co, Cr, Mo, Cu and Nb and compound powder containing two or more of C, Al, Si, Mn, Sn, Ni, Co, Cr, Mo, Cu and Nb. The preparation method comprises the following steps: fully mixing the raw materials; then carrying out mold pressing, isostatic pressing or vibration molding; finally sintering in high-purity hydrogen or a mixed atmosphere of the high-purity hydrogen and nitrogen at 850-1,200 DEG C; carrying out heat preservation for 30-300 minutes. The preparation method is simple in process, rapid sintering of iron compound powder is achieved at relatively low temperature, wear-resistant alloy, high-temperature alloy, silicon steel, high-strength spare parts for automobiles and other special steel products can be manufactured, and the production cost is low.