The invention discloses preparation and application of sodium alginate-based aerogel globules. The adsorbent material is prepared by a method including the steps of: well mixing sodium alginate and pectin powder, adding deionized water and stirring well, standing, dropwise adding the mixed aqueous solution into a calcium salt aqueous solution at a constant speed by using a peristaltic pump, soaking for several hours, separating out hydrogel globules, washing the hydrogel globules with deionized water, air-drying the hydrogel globules, and freeze-drying the hydrogel globules. The aerogel globules prepared by the method have a good adsorption effect on heavy metal ions such as Cd (II), Pb (II) and Cr (III), are an environment-friendly adsorption material, can be applied to multiple fields such as sewage treatment, food processing and biochemical engineering, and have the outstanding advantages of simplicity in preparation, high safety, low cost, easiness in separation, high adsorption capacity, stable adsorption effect and the like.