Mixed calcium oxalate and carbonate apatite stones are very common and are more likely to recur. Preventive suggestions: 1. Drink a lot of water Drink at least 2000ml of water daily (equivalent to a thermos bottle) to ensure that the daily urine volume is more than 2000ml; 2. Limit sodium salt Sodium salt can cause increased urinary calcium excretion, so the daily consumption of sodium chloride (salt) should not exceed 5 grams, avoid MSG, chicken essence; 3. Avoid oxalic acid foods, including amaranth, spinach, rhubarb, mango, strawberries, sesame, cocoa, chocolate, tea, nuts (chestnuts, almonds, walnuts, etc.), which should be avoided or eaten sparingly; 5. Obese people should reduce their body weight; 7. Regular physical examination The urinary ultrasound should be routinely reviewed every year.