The invention discloses a method for preparing a novel high-efficiency heavy metal ion sorbent-carbonic hydroxyl apatite: washing egg shells, drying, and crushing them into below 30 meshes, adding egg shell powder into phosphoric acid in the molar ratio of 1 to 1, calculated by CaCO3, controlling pH value at 1-3, controlling temperature at 30-40 deg.C, and reacting for 2-3 hours, where reaction equation: CaCO3+H3PO4=CaHPO4+CO2+H2O, filtering out nonsoluble matters, adding in urea and Ca(OH)2 powder in the molar ratio of 1 to 1, regulating the pH value to 9-12 with 1mol/L NaOH solution, preserving heat at 50-60 deg.C for 24 h, where chemical reaction formula: CaHPO4+(NH2)2CO+Ca(OH)2-Ca10{(PO4)6-x,(CO3 OH)x}(OH)2, cooling reaction product, and then washing with 1% NH4Cl solution to neutral, drying at 60 degrees centigrade, crushing and obtaining carbonic hydroxyl apatite powder.