A method for removing ammonia nitrogen and recovering rare earth from a low-concentration solution containing ammonium and rare earth comprises the following steps: determining the ammonia nitrogen content and the rare earth content in the solution, adding one or a combination of sodium hypochlorite, calcium hypochlorite and hypochloric acid according to a weight ratio of ammonia nitrogen to available chlorine of 1:7-1:9, and adding fine grains of a solid adsorbent capable of well absorbing rare earth ions; continuously stirring, adjusting the pH for clarification and settlement of sediments comprising the adsorbent and the like, and filtering or putting an obtained supernatant in a liquid storage transit pool; ageing an obtained filtrate for 1-24h, determining the pH value, the ammonia nitrogen content, the rare earth content and the available chlorine content of the solution, and adding to a discharge pool after standard reaching; and putting the obtained settlements or slurry in a precipitate dissolving pool, dissolving the rare earth of an acid or an acid-acid mixed solution, transferring the supernatant to a precipitating pool for a rare earth recovery process, wherein insoluble substances are the fine grains of the adsorbent. The method has the advantages of simplicity, feasibility, low material cost and good treatment effect, and can satisfy treatment requirements of most low-concentration wastewater containing ammonia and rare earth.