The specific usage of magnesium sulfate topical application needs to be decided according to the specific preparation of magnesium sulfate. For example, if it belongs to magnesium sulfate powder, the specific usage in this case is to pour magnesium sulfate powder into warm water, the ratio of warm water should be 1:4 at this time, and then fully stir to make the magnesium sulfate powder completely dissolved in warm water. With a towel dipped in wet after the local hot compress, can play an effective anti-inflammatory, swelling effect. But if the magnesium sulfate injection can also be directly poured into warm water, the specific ratio is also 1:4, and then a towel dipped in wet after the local hot compress. Of course, you can also directly pour magnesium sulfate injection in dry gauze, and then make the pure liquid magnesium sulfate injection for local hot compress, this can also play an effective anti-inflammatory, swelling purpose.