  We propose a unified approach to study meson, nucleon and $\Delta$-baryon
properties at zero and finite temperatures in the context of hard-wall AdS/QCD
model. We first combine some previous works dealing with mesons and baryons
separately, and introduce a new parameter~$\xi$ so that the model could give a
universal description of spectrum and couplings of both sectors in a
self-consistent way. All observables calculated numerically show reasonable
agreement with experimental data. We then study these observables at nonzero
temperature by modifying the AdS space-time into AdS-Schwartzchild space-time.
Numerically solving the model, we find an interesting temperature dependence of
the spectrum and the couplings. We also make a prediction on the finite
temperature decay width of some nucleon and $\Delta$ excited states.
