Most of the molecules in water-absorbing resin are hydrophilic, and the hydrophilicity is also strong, which has the ability to absorb and capture more water in the air. The resin is a polymer with a fibrous structure and many pores in it. Under dry conditions, the fibers of this resin will curl and shrink to a certain extent, making the overall volume smaller. And in the presence of water, under the effect of capillary action and infiltration, the molecules on the surface of the resin fiber combine with water molecules in the form of molecular force, and the pores are able to enter a large amount of water, which makes the water-absorbing resin swell significantly and increase in weight after water absorption.