The SMPU-OOBAm composites were also found to show self-healing properties in this work. As shown in Figure 12, a specimen with a H pattern was prepared using sample P2. First, the sample was cut into two parts before testing (Figure 12), which were subsequently placed together. When the temperature was increased to 80 °C for 10 min, the sample became soft because of the crystal-melting of the soft segment of SMPU. When heated to 100 °C, the gap between the two cut parts gradually decreased. When the temperature reached 130 °C and the samples had been treated for 10 min, the two cut parts joined together completely (see Figure 12c). After cooling to room temperature, the healed sample was obtained (see Figure 12d). Thus, SMPU-OOBAm exhibits thermal-induced self-healing properties. According to the described structure and morphological analysis, the self-healing process is a thermal-induced self-healing mechanism, which can be explained as follows: the OOBA forms an isolated phase, and the SMPU matrix provides the backbone. When the temperature increases to 100 °C, the crystalline OOBA enters the LC state, and a good fluidity is obtained in OOBA molecules at 130 °C. Thus, the OOBA molecules bleed from the SMPU matrix and spontaneously enter the gap. After cooling to room temperature, the OOBA molecules in the gap form crystals via the crystallization process. Therefore, the gap between two cut parts can be sealed. Therefore, the SMPU-OOBAm composites might also have many promise self-healing applications in the fields of flexible printed circuit, self-protecting textiles, and self-healing concrete.