Preparation process of magnesium potassium alginate

The invention discloses a preparation process of magnesium potassium alginate. The preparation process is characterized by comprising steps as follows: (1) an excessive amount of alginic acid and compound potassium salt are subjected to a neutralization reaction for 15-20 min; (2) an excessive amount of magnesium carbonate is added for a neutralization reaction; (3) centrifugation is performed after complete reaction, and a centrifuged product is roughly crushed and dissolved in water; (4) after complete dissolution, centrifugation is performed, water insoluble substances are removed, and ethanol precipitation is performed on a water solution; (5) finally, the magnesium potassium alginate is prepared through centrifugation, freeze drying and crushing. The magnesium potassium alginate contains alginic acid, magnesium ions, potassium ions, carbonate and bicarbonate radical in the molecule structure, has biological activity of magnesium, potassium and alginic acid, has multiple functions of protection of stomach and intestinal mucosa, neutralization of gastric acid, reduction of blood pressure, a magnesium replenisher and the like, is a high-quality crude drug and has good new drug and health-care food development value.