  By considering the steady-state Novikov-Thorne model, we study thin accretion
disk processes for rotating hairy black holes in the framework of the Horndeski
gravity. We obtain the electromagnetic properties of accretion disk around such
black holes and investigate the effects of the hair parameter $h$ on them. We
find that by decreasing the hair parameter from the Kerr limit,
$h\rightarrow0$, the radius of the innermost stable circular orbit decreases
which makes thin accretion disks around rotating hairy black holes in Horndeski
gravity more efficient than that for the Kerr black hole in general relativity.
Furthermore, using the numerical ray-tracing method, we plot thin accretion
disk images around these black holes and investigate the effects of hair
parameter on the central shadow area of accretion disk.
