Method for precipitating rare earth carbonate

The invention relates to a method for precipitating rare earth carbonate, belonging to the field of production technology of rare earth carbonate. The method comprises the following steps of: adding sodium carbonate into rare earth liquid; precipitating the rare earth metal ions until the concentration of the rare earth metal ions in the supernate is 0.2-0.002mol/L; continuously precipitating by taking a sodium bicarbonate solution as a precipitator until the pH value of the supernate is 6-7; and dehydrating the precipitate, and washing to obtain the rare earth carbonate. In the rare earth precipitation process, the rare earth carbonate with low content of calcium oxide and calcium oxide is obtained by combining sodium carbonate and sodium bicarbonate as a precipitator; and after thorough precipitation, the concentration of rare earth ions in the mother liquid is less than 0.0001mol/L.