The impact of nanoconfinement on the dynamic and glass transition of polymers has been found altered in thin films and on the bulk free surface. Confined polymer in nanoparticles is an important system of application in water-borne environmental-friendly coatings. In this work, we discuss method to probe the large scale dynamic of nanoconfined polystyrene in close-packed structure of nanoparticles. We probe the deformation of polystyrene nanoparticles by applying stress at nano-scale level quantified via small-angle neutrons scattering technique. We extract information about the relaxation of the polystyrene confined in nanoparticles and compare it with the relaxation of the same polymer in bulk.