Abstract: The poor degradability of conventional plastics is intensifying the global environmental burden. Although bio-based biodegradable materials are considered one of the alternatives, their long-term application remains constrained by high costs and lengthy degradation cycles. Bamboo fiber, derived from natural sources and renewable, faces technical bottlenecks in processing, as its dense intramolecular hydrogen bonding network renders it non-thermoplastic and unsuitable for direct thermoforming. To address these issues, this study adopted a new strategy based on dynamic covalent chemical bonds to construct an imine network structure. Bamboo fiber was first extracted via chemical methods, followed by selective oxidation with NaIO₄ to introduce aldehyde groups. Dynamic imine crosslinked structure was then formed through Schiff base reaction, and finally, bamboo fiber-based plastic was prepared by hot pressing. The results show that the introduction of dynamic imine bonds successfully replaced part of strong hydrogen bonds in cellulose, enabling material reshaping through exchange reaction of dynamic covalent bonds via hot pressing. The obtained bamboo bioplastic exhibits good stability, outstanding mechanical properties (tensile strength up to 40.3 MPa), hydrophobic performance (water contact angle up to 101.2°, water absorption rate as low as 1.25%), and demonstrates clear degradability in outdoor soil burial experiments. This study provides a new technological pathway for developing all-biomass-based plastics that combine high performance, processability, and environmental friendliness.