In this study, carbon fiber/alumina/shape memory polymer (SMP) hybrid nanocomposites were developed with added short carbon fiber (7 wt%) and alumina nanoparticles (0.0–2.0 wt%) for improving the weak mechanical properties of TPI bulk. The shape memory properties and the effect of the weight fraction of alumina nanoparticle and chopped carbon fiber on the mechanical and thermal properties of the developed SMP hybrid nanocomposites were investigated by static tensile tests, mechanical cyclic tests and thermo-mechanical cyclic tests. The test results demonstrate that the SMP hybrid nanocomposites with chopped carbon fiber (7 wt%) and alumina nanoparticles (1 wt%) exhibit superior mechanical and thermal properties compared with other samples, and a good shape memory property was obtained in the developed nanocomposites.