The prerequisite for intravenous potassium supplementation is a urine output of 30 ml per hour or more than 500 ml per day. Intravenous potassium supplementation is a very important treatment for patients with hypokalemia and other causes of low potassium, but it also has a prerequisite, i.e., urine supplementation. It means that the patient’s hourly urine output needs to reach 30 ml or the daily urine output is more than 500 ml, and the purpose of doing so is to avoid causing hyperkalemia. After entering the body, potassium ions will eventually be metabolically regulated through the kidneys, that is, eliminated from the body in the form of urine. If the patient’s urine output is insufficient, potassium ions cannot be eliminated from the body normally, and excessive accumulation of potassium ions in the body may cause hyperkalemia.