  Context. In September 2022, the transient neutron star low-mass X-ray binary
XTE J1701-462 went into a new outburst. Aims. The objective of this work is to
examine the evolution of the accretion geometry of XTE J1701-462 by studying
the spectro-polarimetric properties along the Z track of this source. The
simultaneous observations archived by the Insight-Hard X-ray Modulation
Telescope (HXMT) and the Imaging X-ray Polarimetry Explorer (IXPE) give us the
opportunity. Methods. We present a comprehensive X-ray spectro-polarimetric
analysis of XTE J1701-462, using simultaneous observations from IXPE,
Insight-HXMT and NuSTAR. For IXPE observations, two methods are employed to
measure the polarization: a model-independent measurement with PCUBE and a
model-dependent polarization-spectral analysis with XSPEC. The corresponding
spectra from Insight-HXMT and NuSTAR are studied with two configurations that
correspond to a slab-like corona and a spherical shell-like corona,
respectively. Results. Significant polarization characteristics are detected in
XTE J1701-462. The polarization degree shows a decreasing trend along the Z
track, reducing from (4.84 $\pm$ 0.37)% to (3.76 $\pm$ 0.43)% on the horizontal
branch and jumping to less than 1% on the normal branch. The simultaneous
spectral analysis from Insight-HXMT and NuSTAR suggests that the redistribution
between the thermal and Comptonized emission could be the reason for the PD
evolution along the Z track. Based on the correlated spectro-polarimetric
properties, we propose that this source likely has a slab coronal geometry and
the size/thickness of the corona decreases along the Z track.
