Diabetes mellitus non-ketotic hyperosmolar syndrome, the basic etiology is absolute or relative insulin insufficiency, under the action of various triggers, blood glucose rises significantly, causing osmotic diuresis, so that a large amount of water and electrolyte loss. It is recommended to seek prompt medical attention to replenish body fluids and lower blood glucose under the guidance of a doctor. Diabetes mellitus non-ketotic hyperosmolar syndrome is treated with rapid rehydration to expand blood volume, including oral drinking water and intravenous rehydration, rehydration at the same time need to pay attention to the patient’s cardiac function, to avoid triggering heart failure, control osmolality to gradually decline, to avoid the emergence of cerebral edema. Electrolyte acid-base balance such as blood potassium needs to be maintained. It is also necessary to give intravenous glucose water to reduce the probability of patients’ hypernatremia. During treatment, attention is paid to monitoring blood electrolytes and blood glucose. It is recommended that the patient go to the hospital in time to seek medical treatment under the guidance of the doctor.