We reviewed the data of an 18-year-old male patient complained of weakness of limbs and hypokalemia for 6 months. CT scan revealed left adrenal adenoma. He was diagnosed as primary aldosteronism(PA). Laboratory tests showed hypokalemia and hyperaldosteronemia. After potassium supplement and blood pressure lowering treatment, laparoscopic resection of the left adrenal adenoma was performed, and severe hyperkalemia occured 2 hours after surgery(maximum serum potassium 7.02 mmol/L). After hyperrisotonic glucose+ insulin(10% glucose 200 ml+ 50% glucose 40 ml+ insulin 8U)+ cation exchange resin(Sodium Polystyrene Sulfonate 20 g) treatment, serum potassium returned to normal range within 12 hours. The plasma aldosterone, blood potassium and blood pressure returned to normal during the 5-month follow-up. According to the experience of this case report, after resection of aldosteronoma, the changes of serum electrolyte should be closely monitored, the occurrence of hyperkalemia should be vigilant.