  High energy X-ray telescope (HE) is one of the three instruments of
Insight-HXMT(Hard X-ray Modulation Telescope) payload. The HE detector (HED)
array is composed of 18 actively NaI(Tl)/CsI(Na) phoswich scintillators with a
total geometric area of ~ 5100cm^2 and cover the energy range 20-250 keV. In
this paper we describe the on-ground detector-level calibration campaigns and
present the principal instrument properties of HEDs.
