We investigated spatial distribution of spontaneous polarization in ferroelectric PbTiO_3 nanosprings with helicity using a real-space phase-field modeling based on Landau-Ginzburg theory. Without external loading, polarizations are aligned along the line of nanospring due to dominating depolarizing field. On the other hand, the tensile loading brings about the polarization vortices with a right-handed chirality on the cross-section of nanospring, leading the formation of polarization superhelix. We also showed that the compression inversely gives rise to the polarization superhelix with a left-handed chirality. These indicate that the loading conditions can tailor the chirality of polarization superhelix in ferroelectric nanosprings.