A method for preparing porous fluorapatite ceramic adsorbing radioactive nuclide is characterized by including: using the materials in percent by weight: 50-80% of calcium pyrophosphate, 4-26% of calcium fluoride and 16-45% of calcium carbonate, and mixing, ball-milling, drying, press-forming, calcining, grinding, and screening to obtain fluorapatite powder; mixing the fluorapatite powder with polyethylene glycol solution, methyl cellulose solution and hydrogen peroxide solution, and performing microwave assisted pore-forming, drying and the like to obtain a porous fluorapatite ceramic blank; preparing porous fluorapatite ceramic adsorbing material via normal pressure sintering. The porous fluorapatite ceramic adsorbing material prepared herein has the advantages of high radiation stability, good thermal stability, high mechanical and chemical stability and the like, also has high specific surface energy and nuclide adsorbing capacity and may be used as an efficient adsorbing material for radioactive nuclide in high-radioactive waste liquid, thus effectively protecting human health and ecological environment.