  Strangeon star model has passed various observational tests, such as the
massive pulsars and the tidal deformability during binary mergers. Pulsar
glitch, as a useful probe for studying the interior structure of pulsars, has
also been studied in strangeon star model in our previous papers, including the
recovery coefficient, the waiting time of glitches and glitch activity. In this
paper, the recovery process of a glitch is described in the strangeon star
model, based on the starquake picture established in Paper I. After the
starquake, the inner motion of the stellar matter would reduce the tangential
pressure in the cracked places at the equatorial plane. The recovery (increase)
of the tangential pressure would be achieved by a viscous flow towards the
cracked places at equatorial plane, which leads to the exponential recovery of
the spin frequency. A uniform viscous flow can reproduce the single exponential
decay observed in some glitches, and the viscous time-scale $\tau$ and the
depth $h$ of the cracking place below the surface can be fitted by the recovery
data. It is found that $h$ increases with glitch size $\Delta\nu/\nu$, which is
expected in the glitch scenario of strangeon stars. The magnitude of the
recovery predicted in this recovery model is also consistent with that derived
from observations. The single exponential decay reproduced by a uniform viscous
flow can be generalized to two or more exponentials by the multi-component of
viscous flows.
