  Gravitational decoupling can add hair to the black holes by adding extra
sources. The quasinormal modes of hairy black hole caused by gravitational
decoupling for the massless scalar field, electromagnetic field, and
gravitational perturbation are investigated. The equations of effective
potential for three perturbations are derived in hairy black hole spacetime. We
also study the time evolution corresponding to the three perturbations, and the
quasinormal mode frequencies are calculated using the Prony method through the
time-domain profiles. By analyzing the influence of the hairs ($\alpha$, $l_0$
and $Q$) for the black holes we studying on quasinormal mode, we find that the
hairs $\alpha$ and $l_0$ decrease the oscillation frequency of the
gravitational wave signal, and the hair $Q$ increase its oscillation
frequency.Furthermore, we have calculated the bounds of greybody factor and
high-energy absorption cross section with the Sinc approximation, which reveals
that the presence of charges ($\alpha$ and $l_0$) generating primary hair can
increase the probability of gravitational radiation arriving spatial infinity,
whereas the charge $Q$ from the extra sources does the opposite.
