PVC is widely used due to its flame retardancy, wear resistance, chemical corrosion resistance, low gas permeability, comprehensive mechanical properties, transparent products, electrical insulation, thermal insulation and sound insulation. However, due to defects in the chemical structure of PVC, resulting in poor thermal stability and low impact strength, PVC stabilization, high performance and functionalization have been receiving much attention. In this paper, the degradation and aging of PVC were first simulated, and then the D-A reaction of ethyl bismaleamic acid (DMA) with degradation of PVC was carried out to achieve the mechanical property repair at the molecular level. The furan ring and PVC were realized by Friedel-Crafts reaction. And D-A reversible reaction with DMA was carried out to realize the thermal reversible self-repair of PVC. DMA materials were synthesized to simulate the aging degraded PVC, and the tensile properties were repaired by DMA materials. The results showed that the repair rates of tensile strength and elongation at break reached 109.8% and 150.3%, respectively. FTIR before and after PVC repair proved that the mechanism of repair reaction was Diels-Alder reaction between degradation of conjugated polyene in PVC and DMA. The friedel-crafts grafting reaction of furan and PVC was realized by microwave irradiation and the reaction conditions were optimized. By replacing the anomalous chlorine atom with furan ring, the unstable structure of PVC was modified, and the stabilization of PVC was realized at the source. Based on the thermally reversible D-A reaction between the furan ring and DMA introduced, the PVC-Fur-DMA self-repair system was constructed. The scratch repair at different temperatures and at different times was observed under a polarizing microscope, which proved that the D-A bond had thermal reversibility and could realize the self-repair of materials.