Moisture plays an important role in fruit preservation. In this study, deep eutectic solvents (DESs) were prepared and DES-based films with the property of buffering moisture variation were fabricated (CG10, CG50). Low-field nuclear magnetic resonance (LF-NMR) analyses and Raman spectra suggested that the water states in DESs and DES-based films transferred from a tight combination to a loose combination during the moisture sorption process. In addition, the moisture sorption capacity (Meq = 2.91) of the film suggested that CG50 possessed water storage capacity and a high effective diffusion coefficient (0.01 mm2 d−1) ensured the easy passing of water molecules through the DES-based films. Furthermore, the fruit preservation experiment using cherry tomatoes as a representative showed that DES-based films as a “buffer pool” not only could inhibit spoilage but also maintain the stable packaging RH, indicating the potential of DES-based films in moisture regulation.