  In this paper, we revisit a scale-invariant extension of the standard model
(SM) with a strongly interacting hidden sector within AdS/QCD approach. Using
the AdS/QCD, we reduce the number of input parameters to three, {\it i.e.}
hidden pion decay constant, hidden pion mass and $\tan\beta$ that is defined as
the ratio of the vacuum expectation values (VEV) of the singlet scalar field
and the SM Higgs boson. As a result, our model has sharp predictability. We
perform the phenomenological analysis of the hidden pions which is one of the
dark matter (DM) candidates in this model. With various theoretical and
experimental constraints we search for the allowed parameter space and find
that both resonance and non-resonance solutions are possible. Some typical
correlations among various observables such as thermal relic density of hidden
pions, Higgs boson signal strengths and DM-nucleon cross section are
investigated. We provide some benchmark points for experimental tests.
