The five principles of intravenous sodium replenishment are as follows: First, how much is needed to replenish, according to the blood gas analysis and the level of sodium ions in the blood, to estimate the amount of sodium ions that need to be replenished in the body, usually according to the formula of sodium replenishment to calculate the amount of sodium needed to be replenished according to the amount of sodium needed to be replenished, and not to replenish too much sodium. Second, the speed of sodium supplementation is usually within the first 24 hours, sodium supplementation should be carried out at full speed, but after the second 24 hours, sodium supplementation needs to be carried out slowly. Third, sodium supplementation should be given under close supervision, and the patient’s heart rate, blood pressure, oxygen saturation, respiration, pulse rate and other monitoring should be carried out during the process of sodium supplementation. If the indications are unstable or once the signs are unstable, the amount of sodium and rehydration solution needs to be replaced in time. Fourth, sodium supplementation should also observe whether there is a change in urine output. Fifth, sodium supplementation should also be used to correct other ionic disorders, such as hypokalemia, hypomagnesemia and so on. In conclusion, several principles of sodium supplementation must be similar to other principles of ion supplementation, so as to achieve the need for how much supplementation, the first crystal, after the colloid, diligent monitoring, after the rehydration fluid.