Abstract: Accelerated aging test was conducted on glass fiber reinforced epoxy resin composite in warm-wet and ultraviolet irradiation environment. The chemical structure, surface element content, surface morphology, glass transition temperature, and bending and tensile properties of the composite were studied by infrared spectrometer, X-ray photoelectron spectrometer, scanning electron microscope, thermal gravimetric analyzer and mechanical testing machine. The results show that in the warm-wet and ultraviolet irradiation environment, the rupture of chemical bond occurred in the resin of composite after aging for 1 440 h, the chemical structure changed and the resin went through the photo-oxidation reactions. With aging time increasing, the surface of composite showed discoloration, cracking and warping deformation features. After aging for 1 440 h, a laminar wave pattern was observed on the surface. With the increase of aging time, the strength and modulus of the composite both increased first and then decreased, and reached the maximum values after aging for 160 h. After aging for 1 440 h, the initial decomposition temperature of the composite was lower than that before aging, the glass transition temperature was about 113.4 ℃, which was 8 ℃ higher than that before aging.