The invention discloses a preparation method and application of Li2O-Al2O3-SiO2 system glass ceramics. The glass ceramics are prepared from, by weight, 58-68 parts of SiO2, 1-4 parts of Al2O3, 1-3 parts of ZrO2, 0.5-1 part of P2O5, 0.5-2 parts of K2O, 0.5-1 part of CeO2 and 25-28 parts of Li2O by adopting oxide as the benchmark. During specific preparation, the materials of all components are weighed in proportion and mixed to be uniform; then founding is carried out for 2 h to 5 h at the temperature of 1,450 DEG C to 1,480 DEG C, and high-uniformity glass liquid is obtained; the glass liquid is subjected to bubble and stripe removal and finally enters a mold for cooling molding. ZrO2 and P2O5 are adopted as a mixed nucleation agent, ZrO2 is mainly used for inducing to form a principal crystalline phase beta-quartz solid solution in a glass system, P2O5 mainly promotes dissolving of ZrO2 in the glass, the nucleation rate is increased, ZrO2 and P2O5 promote each other, and therefore the glass ceramics with finer crystalline grains are obtained. The obtained glass ceramics are high in strength and good in biocompatibility and have high application value.