To obtain the space charge distribution of electrical equipment under a temperature gradient

the one-dimensional cross-linked polyethylene（XLPE） plate samples were taken as examples. The voltage signals representing space charge distributions of XLPE samples under constant temperatures and temperature gradients were measured by a pulse electro-acoustic（PEA） method

then a new recovery algorithm of voltage-acoustic-space charge transformation was derived. The analyses of measured voltage signals characterizing space charge distributions under different constant temperatures indicated that the main components of acoustic in XLPE under temperature of 20～80 ℃ were within 0～35 MHz

and attenuation coefficient of acoustic signal in this range had a one-dimensional linear relationship with temperature. Based on this phenomenon

the transfer function calculation matrix of acoustic propagation process in traditional space charge recovery model under constant temperature was revised

and a new recovery algorithm for space charge measurement under temperature gradient was derived. According to recovery results of voltage signals for space charge in XLPE under different temperature gradients

space charge distributions in 5 kV/mm without significant charge accumulation was obtained. The accuracy of new recovery algorithm was verified by comparing the internal electrical distributions calculated by Poisson equation and theoretical value inside XLPE. Finally

the new recovery algorithm was used to measure and analyze the space charge in XLPE under DC field

and it was found that a temperature gradient led to significant decrease in space charge accumulation on the high temperature side as well as increase in field strength distortion on the low temperature side.