Novel nanoencapsulated phase change materials (NePCMs) with polydopamine (PDA)-SiO2 hybrid shell material were prepared, and the thickness of PDA layer was highly tunable. The PDA layer was fabricated through oxidative self-polymerization of dopamine in Tris-HCl buffer solution, on preformed NePCMs with SiO2 shell. When Tris-HCl concentration is fixed at 50 mM and dopamine concentration is increased from 2 to 8 g/L, the shell thickness of the obtained NePCMs increases gradually from 27 to 37 nm. Phase change enthalpies of the NePCMs with PDA-SiO2 hybrid shell are reduced slightly with increasing PDA layer thickness, Thermal stability of the as-prepared NePCMs is improved obviously, compared with that of unencapsulated n-octadecane. It is further demonstrated that the NePCMs with PDA-SiO2 hybrid shell can be incorporated into thermo-regulating rigid polyurethane foams with high mechanical performance, due to improved interfacial compatibility and interaction between PDA layer and polyurethane matrix.