To investigate the influence of space irradiation on the properties of J312L structural adhesive， micromorphology， molecular structure， heat resistance， vacuum pollution and mechanical properties of J312L were analyzed by SEM， FT-IR， XPS， TGA， DSC， vacuum outgassing and mechanical test. The irradiation aging mechanism of material was investigated. The results show that the total dose irradiation has a significant effect on the thermal stability， vacuum outgassing and mechanical properties of J312L adhesive. After 1.5×10⁹ rad（Si） γ-ray irradiation from ⁶⁰Co， the tensile shear strength is 4.8 MPa， and the total vacuum mass loss （TML） is 2.36%. Compared to that of the initial， the glass transition temperature and the thermal decomposition temperature （T_d 5%） are reduced by 31 ℃ and 84 ℃， respectively， indicating that the J312L adhesive is dominated by the degradation reactions within high-dose radiation.