The invention relates to the metallurgy field and discloses novel samarium-cobalt-base nano-composite permanent magnetic material. The samarium cobalt base is (Sm, R)1(Co, Fe, Cu, Zr)7 in type and comprises a TbCu7 type structure, and Co is partially replaced by Fe, Cu and Zr; Re is any one of heavy rare earth Lu, Dy and Tb and partially replaces Sm. The preparation method includes steps that 1) mixing raw materials of the samarium cobalt base according to proportion, and smelting to obtain a 1: 7 type samarium cobalt base alloy ingot; 2) ball milling the alloy ingot through a high-energy ball milling technique, mixing with Fe powder according to proportion, and performing high-energy ball milling to obtain nanocrystalline composite magnetic powder; 3) carrying out annealing heat treatment on the nanocrystalline composite magnetic powder. According to the samarium-cobalt-base nanocrystalline permanent magnet material and the preparation method thereof, the soft/hard-magnetic phase composite magnetic powder is prepared through the high-energy ball milling, laser heat treatment and other techniques, a high magnetic energy product is obtained through exchange coupling between the nanocrystalline hard magnetic phase and nanocrystalline soft magnetic phase, and meanwhile, because rare-earth Fe phase is not used, the cost is lowered, and the operation technique is simplified.