High-strength multi-level hydrogel, preparation method and application thereof

The invention relates to the technical field of hydrogel, and particularly discloses a high-strength multi-level hydrogel, a preparation method and application thereof. The preparation method comprises the following steps of: adding polyelectrolyte into water, and mixing the substances uniformly to obtain a polyelectrolyte solution; adding a cross-linking agent into the polyelectrolyte solution tocarry out cross-linking reaction, and then performing freezing to obtain hydrogel; or adding a first strong acid solution or a first metal ion solution into the polyelectrolyte solution, and conducting freezing to obtain hydrogel; unfreezing the obtained hydrogel, soaking the hydrogel into a second strong acid solution or a second metal ion solution, and performing cleaning to obtain the hydrogel. The hydrogel prepared by the method forms a micron-sized hole structure and a hole wall structure of nano-sized grid microfibers, and is hydrogel with a multi-level structure, and the micron-sized holes endow the hydrogel w