Archaeological weathered bones are usually porous and fragile, easily to warp, crack and crumble. To avoid these relic damages, consolidation technology is badly needed. Here, we explored a new consolidation method for weak bone relics using hydroxyapatite as protectant. Briefly, dispersion of calcium oxide mixed with calcium hydrophosphate in alcohol was used firstly to permeate into the fragile bones as precursor of hydroxyapatite consolidant. Then pure water was used to trigger the reaction between calcium oxide and calcium hydrophosphate, which leads to formation of a continuous phase of hydroxyapatite consolidant. By filling and bridging the pores or fissure inside the fragile bones, hydroxyapatite consolidant can act as a reinforcement material. Effects of the mass ratio of calcium oxide to calcium hydrophosphate (1 : 1, 1 : 3, 1 : 4, 1 : 5, 1 : 6, 1 : 7) and the application ways (brushing, drip infiltration and soaking) on the protective performance were investigated by scanning electron microscope (SEM), energy dispersive spectroscope (EDS), X-ray diffraction (XRD) and characterizations of color difference, weight increment, porosity, density and cohesive strength determination. The results showed that the best consolidation performance could be obtained when the mass ratio of 1 : 3 and the brushing consolidation method were adopted. In this case, porosity of the fragile bones decreased by 17.3%. Mass, density and cohesive strength of the fragile bones increased by 38.39%, 34.49% and 16.32%, respectively. Moreover, the color difference of bones is less than 3.0, which is allowable in the field of heritage conservation.