Charging and discharging characteristics of dielectric in space electron radiation environment are closely related to the surface charge exchange process and internal charge transfer process. Surface or internal charge movement of dielectric depends largely on the microscopic characteristics of the material, and space charge and trap are important parameters reflecting the microscopic characteristics of dielectric. In this work, the formation, mechanism, measurement method, existing problems and research status of space charge and trap in insulation material in electronic radiation environment are reviewed. Firstly, the interaction mechanism between incident electron and dielectric material and the formation of deposition charge are briefly introduced. The advantages and disadvantages of radiation-induced conductance model and electron-hole pair generation/recombination model are analyzed. The classical electro-acoustic pulse method (PEA) and " short circuit PEA” and " open circuit PEA” which are suitable for space charge measurement under electron beam radiation are compared with each other and analyzed, and further, the main technical difficulties in designing PEA device under electron beam radiation are reviewed. Secondly, the methods of extracting trap parameters, including thermal stimulation current method, surface potential decay method, space charge decay method are compared with each other.

It is pointed out that the method of injecting the electrons and the method of measuring the surface potential in the same vacuum environment are more suitable for measuring the trap parameters of space dielectric materials. Finally, the scientific problems that need solving in space insulation are prospected from the aspects of theoretical model, parameter characterization and measurement technology.