The reasonable conduction property is beneficial to release the deposited charges by conduction current in di- electric space charging environment, thus the level of the deep charging and the pulse discharge can effectively be weakened and inhibited. A traditional method for conductivity measuring under ground circumstance was used, and both the applied voltage and temperature were varied to determine the dependence of volume conductivity in PTFE modified by different filler contents. The results inferred the volume conductivity was significantly affected by the phenomenon of the percolation conduction, as well as the high-field conduction. The shallow and deep charge traps were considered to be a key factor in volume conductivity variation. In this theory, modified by inorganic semi conductive filler, the distribution of trap density and depth in PTFE can be controlled to achieve the ideal temperature dependent conduction property and high-field conduction property, which will finally lead to gentle release of the deposi ted charges while the electrostatic field reaches the conductivity-variation threshold.