There is no quick way to rehydrate a baby, and rehydration treatment should be given according to the type of dehydration, which can be carried out through oral, nasal feeding and intravenous fluids. Dehydration can be clinically categorized into hypotonic dehydration (simultaneous loss of water and sodium, but more sodium than water), hypertonic dehydration (simultaneous loss of water and sodium, but more water than sodium) and isotonic dehydration (proportional loss of water and sodium). 1. Hypotonic dehydration: Supplementation of hypertonic fluid and saline solution, mainly through intravenous drip, can replenish water faster and relieve symptoms. 2. Hypertonic dehydration: hydration is the main focus, supplemented by sodium. Patients can be rehydrated by oral or nasal feeding, and supplemented with 5% dextrose sodium chloride and 5% dextrose solution through intravenous infusion. If necessary, alkaline fluids and potassium should also be supplemented at the same time. A combination of multiple ways of rehydration is necessary to complete rehydration more quickly. 3. Isotonic dehydration: patients should be supplemented with isotonic solutions, such as 0.9% sodium chloride solution, which can also play a role in rapid rehydration. Children suffering from dehydration are advised to consult a doctor in time for examination, and under the guidance of the doctor to take the appropriate way of rehydration therapy, as severe dehydration can be life-threatening.