In this talk, I will review the viable parameter space of the scalar sector in the type-II seesaw model. In identifying the allowed parameter space, constraints from low energy precision measurements, theoretical considerations and the 125-GeV Higgs data are taken into account. These tools prove effective in constraining the model parameter space. Moreover, the triplet also offers a rich collider phenomenology from having additional scalars that have unique collider signatures such as the same-sign dilepton, the same-sign W and the multilepton signatures. By investigating various LEP and LHC measurements, the most updated constraints over the whole range of parameter space of the type-II seesaw model will be shown.