The invention relates to a high-grade garden porcelain made by bone-china production waste and its preparation method, and belongs to the porcelain technical field. The green body of the high-grade garden porcelain made by bone-china production waste is chemically prepared from, by weight percent, 30-35% of SiO2, 8-14% of Al2O3, 12-19% of Fe2O3, 18-24% of CaO, 13-20% of P2O5, 1-5% of KNaO and trace impurity. The high-grade garden porcelain made by bone-china production waste has the advantage of changing performance of waste sludge in bone-china production; the porcelain does not need to glaze, and is not easy to crack; the porcelain is nature in texture, smooth in hand feeling, good in both water transmittance and water color, and excellent in color generation; meanwhile, the invention further provides a simple and easy-practiced, energy-saving and environment-friendly preparation method.