  We analyze three observations of GRS 1915+105 in 2017 by Insight-HXMT when
the source was in a spectrally soft state. We find strong absorption lines from
highly ionized iron, which are due to absorption by disk wind outflowing at a
velocity of $\sim$ 1000 km s$^{-1}$ along our line of sight. Two of the three
observations show large amplitude oscillation in their light curves and the
variation pattern corresponds to state $\kappa$ of GRS 1915+105. From
time-averaged and flux-resolved analysis, we find that the variation of the
ionization state of the disk wind follows the X-ray continuum on timescales
from hundreds seconds to months. The radial location of the disk wind is
consistent with thermal driving. The mass-loss rate due to the outflowing wind
is comparable to the mass accretion rate in the inner disk, which demonstrates
the important role of the disk wind in the disk accretion system.
