Abstract: Carbon fiber reinforced polymer (CFRP)@glass fiber reinforced polymer (GFRP) hybrid composite rod plays the advantages of carbon fiber (such as high mechanical and fatigue performances) and glass fiber (such as low cost and high deformation capacity) and has great application potential in bridge and ocean engineering, such as cross-sea bridge cable. In view of the long-term performance evolution of CFRP@GFRP hybrid composite rod under the service environment, the present paper adopted the experimental acceleration method to study the water absorption and interface shear performance evolution of CFRP@GFRP hybrid composite rod under the distilled water environment. The results show that the absorption behavior of hybrid composite rod is in accordance with Fick law. The diffusion coefficient of glass fiber shell is the largest, carbon fiber core is the second, and the hybrid composite rod is the smallest due to the water absorption barrier between the shell/core interface layer. Immersed in distilled water leads to the decrease of the interface shear strength of core, shell/core and shell layers. This is attributed to the water molecules combined with the resin matrix in the form of hydrogen bond to form the bond water, resulting in the hydrolysis and plasticization of the resin matrix and the debonding of the fiber/resin interface. The prediction model of interface shear strength of hybrid composite rod was established in three typical bridge service environments based on the accelerating theory of Arrhenius.