  We investigate the double Higgs production and decay at the $14~ {\rm TeV}$
LHC and $33~ {\rm TeV}$ HE-LHC in both the standard model and Randall-Sundrum
(RS) model. In our calculation we consider reasonably only the contribution of
the lightest two Kaluza-Klein (KK) gravitons. We present the integrated cross
sections and some kinematic distributions in both models. Our results show that
the RS effect in the vicinities of $M_{HH} \sim M_{1}$, $M_{2}$ (the masses of
the lightest two KK gravitons) or in the central Higgs rapidity region is quite
significant, and can be extracted from the heavy SM background by imposing
proper kinematic cuts on final particles. We also study the dependence of the
cross section on the RS model parameters, the first KK graviton mass $M_1$ and
the effective coupling $c_0$, and find that the RS effect is reduced obviously
with the increment of $M_1$ or decrement of $c_0$.
