A spinal fusion cage, has at least hydroxyapatite ceramic, a grain size of the hydroxyapatite ceramic is less than 300 nm. The spinal fusion cage of the invention improves mechanical strength and especially fracture toughness, overcomes brittleness of a conventional hydroxyapatite ceramic, and meets mechanical requirements for the spinal fusion cage. Meanwhile, the spinal fusion cage of the invention maintains biological activity of hydroxyapatite, and facilitates bone fusion with bones within a body.