Abstract: The low mechanical strength of shape memory polymers (SMP) are insufficient to meet the standards of most commercial composites today, severely limiting their use in many advanced applications. Therefore, in order to prepare high-performance SMP composite materials, a novel nano-filler SiO₂@PDA was prepared by surface modification of nano-silica (SiO₂) with polydopamine (PDA), its structure and properties were characterized by SEM, XPS and FTIR, respectively. Shape memory composites based on trans-1,4-polyisoprene (TPI) were prepared by filling SiO₂ and SiO₂@PDA into TPI as nano-fillers. The thermal stability, comprehensive mechanical properties and shape memory properties of TPI/SiO₂ and TPI/SiO₂@PDA composites were systematically studied. The results show that PDA modification enhances the dispersion and interfacial interaction of SiO₂ in the TPI matrix, so that the thermal stability and mechanical properties of the TPI/SiO₂@PDA composites can be improved, while maintaining good shape memory performance. The impact strength and tensile strength of the composite reach the maximum values when the SiO₂@PDA content is 1.5% (based on the mass of TPI, the same below), which are 43.5% and 25% higher than that of the neat TPI, respectively. Moreover, shape fixation rate (R_f) and shape recovery rate (R_r) of the composites are over 97%.