MIL-101(Cr)/polyacrylamide/chitosan (named as MIL-101(Cr)/PAM/CSA) composite aerogel with large surface area is synthesized by incorporating MIL-101(Cr) into polyacrylamide/chitosan composite aerogel and used for efficient 2, 4-Dichlorophenoxyacetic acid adsorption. MIL-101(Cr)/PAM/CSA and polyacrylamide/chitosan composite aerogels exhibit good underwater superelastic properties with multi-level network synergistic cross-linking. After introducing MIL-101(Cr) with the mass loading of 30%, the specific surface area of the composite aerogels enlarge from 58.15 m2 g−1 to 310.94 m2 g−1. MIL-101(Cr)/PAM/CSA exhibits high adsorption capacity of 302.45 mg g−1 for 2, 4-Dichlorophenoxyacetic acid (2, 4-D) and stable recycling capability. This work provides a general and effective method to synthesize composite aerogel with underwater superelastic properties, hierarchical pores and large surface area, promising to realize regeneration after compression with reduced solvent usage and costs.