<p>Biopolymer aerogels have shown broad prospects in efficient thermal management. However, their inherent flammability imposes limitations on practical utilization. In this study, a gelatin-based composite aerogel (Zn-MOF-DA/GA) was successfully prepared by dopamine-modified Zn-MOF nano-reinforcement and multiple crosslinking in gelatin solution. The Zn-MOF-DA component not only facilitated the uniform dispersion of MOF nanoparticles but also enhanced interfacial molecular interactions through multifunctional groups and intrinsic physical properties. The as-prepared aerogel with a hierarchical porous structure, low bulk density, and high mechanical strength exhibits excellent thermal insulation performance (33.02–37.62 mW·m⁻¹·K⁻¹) and anisotropic thermal properties. Moreover, the nano-porous Zn-MOF-DA significantly improved the flame retardancy of composite aerogel, reducing the peak heat release rate and total smoke release by 48% and 96%, respectively, compared to gelatin aerogel. The design strategy of multi-crosslinking and nano-reinforcement provides a broad prospect for sustainable aerogels in the field of thermal management and fire safety.</p> Graphical abstract <p></p>