The invention discloses a traditional Chinese medicine sustained-release capsule for treating cystolith and a preparation method thereof and belongs to the technical field of medicines. The traditional Chinese medicine sustained-release capsule comprises the following traditional Chinese medicine raw material effective components: endothelium corneum gigeriae galli, unprocessed radix astragali, unprocessed white peony root, rhizoma anemarrhenae saltpeter, mirabilite, herba desmodii styracifolii, stigma maydis, folium pyrrosiae, abrus herb, poria, plantain herb, lygodium japonicum herb, rhizoma imperatae, herba incarvller, small centipeda herb, rhizoma corydalis, talcum powder, microcrystalline methylcellulose, ethyecellulose, glyceride and polyethylene glycol. The preparation method of the traditional Chinese medicine sustained-release capsule comprises the following steps: preparing raw materials, extracting traditional Chinese medicine raw material effective components, preparing a traditional Chinese medicine raw material effective component containing pill core, preparing a traditional Chinese medicine raw material effective component sustained-release micro pill, and filling a capsule. A method of eliminating lithiasis, balancing blood pH and improving lithiasis physique is used for starting the treatment of cystolith. The selected traditional Chinese medicine materials are reasonable in compatibility; the traditional Chinese medicine sustained-release capsule is prepared by using modern advanced sustained-release medicine preparation technique; the traditional Chinese medicine sustained-release capsule is high in action speed and high in stability, and is extremely suitable for patients with cystolith.