The disclosure belongs to the field of preparation of radioisotopes for medical uses and relates to a method for extracting lead-212 and bismuth-212 from a thorium-232 decay chain, including: passing a solution containing thorium-232 decay chain substance through an anion exchange resin column, the solution containing thorium-232 decay chain substance containing halogen ions, and a concentration of hydrogen ions in the solution containing thorium-232 decay chain substance being more than 0.01 mol/L, lead-212 and bismuth-212 being adsorbed by the anion exchange resin column and other nuclides passing through the anion exchange resin column without being adsorbed; and introducing eluting agents to desorb lead-212 and bismuth-212 from the anion exchange resin column, so as to obtain lead-212 and bismuth-212 by separation and extraction. The disclosure can simultaneously extract lead-212 and bismuth-212 with a high extraction speed and high purity, and is not easy to cause organic pollution of products.