The cooperative self-assembly of polystyrene-b-poly(4-vinylpyridine) block copolymers (BCPs) and gold nanopartides (AuNPs) confined within the emulsion droplets is studied by combining both the experiments and Monte Carlo simulations. The results indicate that the entropic interaction between the AuNPs and BCP domain is a critical parameter to dominate the spatial arrangement of AuNPs and the nanostructure of the hybrid nanopartides, which can be utilized to design novel hierarchical hybrid nanopartides. Based on this theoretical observation, a large number of unique Janus hybrid nanopartides, including pupa-like nanopartides with AuNPs concentrated at one pole of the particles, spherical nanoparticles with AuNPs enriched in a bulge on the sphere surface, and the gourd-like, clover-like, and four-leaf-clover-like nanoparticles from the further hierarchical assembly of small hybrid Janus nanopartides, are fabricated via three-dimensional (3D) confined self-assembly.