Abstract: Based on the new diagnosed technology of current integral charge (DCIC), this paper studies the dynamic charges behavior and high-field conduction characteristics of XLPE insulation under different electric fields through the test principle and system construction. The results show that the dynamic charges variation q(t) under different electric fields reveals the characteristics of instantaneous charging current, absorption current, and conduction current of XLPE. According to the results of instantaneous charge q₀, the static relative dielectric constant ε_r of XLPE insulation medium can be calculated as 2.2. The current is obtained by differentiating the dynamic charges. The high field conduction results show that the conductivity of the Ohmic region of XLPE is 3.79×10^–15 S/m. According to the high field conduction, the charge injection threshold of XLPE is estimated to be about 10 kV/mm. These studies are consistent with the results reported in the literature and verify the accuracy and effectiveness of the DCIC−q(t). In addition, the space charge distribution results of XLPE by PEA present the same trend with the q(t) for charge increase with the electric field. The DCIC−q(t) technique has the advantages of high sensitivity and wide range. Finally, the charge accumulation characteristics of the insulation of different water-tree aged whole cables (6.6 kV) are analyzed by using the DCIC−q(t) method. Aging of the whole cable insulation can be evaluated by the change of the charge accumulation.