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大型超导磁体中采用的绝缘材料需要在极低温和强辐射的环境下保持良好的电气以及机械性能.文中以氰酸酯和双酚F环氧共混作为基底,无硼玻璃纤维进行增韧改性,采用真空浸渍工艺制备出改性的玻璃增强环氧树脂绝缘材料(glass fibre reinforced polymer,GFRP),并对其进行1 MGy和5 MGy的γ射线辐照.在20～300K温度环境下对环氧复合材料的介电性能以及电导电流特性进行测试分析.测试结果表明,温度降至20K过程中,介电损耗 γ 峰对应的频率变化不大,幅值随着温度降低呈整体下降趋势,且高频区域没有出现新的损耗峰,GFRP材料的环氧-玻璃纤维界面性能保持良好.200K以下材料的电导率低,空间电荷限制电流阈值场强高;辐照对材料的作用表现为先交联后降解的过程,以降解过程为主,材料整体耐辐照性能较高.“,”Insulation materials used in large scale superconducting magnet need to maintain sound electric and mechanic performance under cryogenic temperature and intense γ radiation conditions. In this research, cyanate ester and bisphenol F epoxy resin were mixed as matrix, which was reinforced by boron glass fibre, and the glass fibre reinforced polymer (GFRP) was manufactured by vacuum pressure impregnation method and irradiated by γ rays for 1 MGy and 5 MGy. Dielectric properties and conduction current were tested and analysed at temperatures within 20～300 K. The test results shown that, as sample being cooled to 20 K, the γ peak of dielectric loss presented little change in its corresponding frequency, and the amplitude keeps decreasing with temperature. No loss peak was detected within the high frequency range, which indicates cryogenic temperature had little effect on interface between epoxy resin and glass fibre. The conduction current was weak at temperatures below 200 K and the space charge limited current threshold field was increased; crosslinking reaction was observed during irradiation and followed by degradation, and the later dominated the whole process generally, and the material was proved to be with high resistance to irradiation.