<p>Although poly(urethane-urea) elastomers (PUEs) possess excellent mechanical properties and durability, their inherent flammability and inability to self-repair after damage significantly limits their applications in high-end fields. To address this challenge, this study employs a supramolecular chemistry approach by simultaneously incorporating multiple hydrogen bonds as dynamic cross-linking points and a phosphorus-nitrogen synergistic flame-retardant structure into the poly(urethane-urea) network. The multiple hydrogen bonds endow the material with efficient intrinsic self-healing capability, while the phosphorus-nitrogen flame retardant ensures outstanding thermal stability and flame resistance, leading to the successful synthesis of a high-performance multifunctional poly(urethane-urea) elastomer. Experimental results demonstrated that when the content of the flame retardant diethyl (2-((2-aminoethyl)amino)ethyl)phosphoramidate (DEPTA) was 10 wt%, the resulting PUE/10%DEPTA achieved a V-0 rating in the vertical burning test, with a limiting oxygen index (LOI) of 30%. Concurrently, the elastomer maintained good toughness, exhibiting a tensile strength of 27.3 MPa, an elongation at break of 601%, and a self-healing efficiency of up to 94.46%. This breakthrough shows significant promise for advanced engineering applications that demand fire safety, structural durability, and extended service life through self-repair.</p>