The highly flexible polytetrahydrofuranediol (PTMG) substrate was reacted with furfuryl glycidyl ether-2-furanethylamine (FGE-FA) to obtain the polyurethane prepolymer of tetrahydrofuran structure, and then it was reacted with bismaleimide of dienophile structure to prepare high density Diels-Alder (DA) self-healing polyurethane (PU-DA) with dynamic covalent bond. The PU-DA was characterized by FTIR, DSC and OM, and the performance of PU-DA was tested by electronic universal testing machine. The results show that the forward and reverse reaction temperatures of PU-DA are 70℃ and 132℃, respectively, after the introduction of DA dynamic covalent bond. PU-DA has good performance in remodeling, swelling solubility and multiple self-healing. Cracks of the damaged PU-DA could basically be healed by heating at 70℃ for 4 h, meanwhile, the first repair rate could 94.8%, and the third repair rate was still higher than 70%.

Keywords： organic polymer materials ; self-healing ; Diels-Alder reaction ; polyurethane ; thermal reversibility