Building reinforcement projects are designed to meet the requirements of modern sustainable development. However, the weak bonding performance of continuous glass fiber textiles to mortar presents a challenge in the manufacturing of GTRM composites, hindering their development and application. In this study, the gradient composite design technique was used to modify the interface transition zone between continuous glass fiber textile and mortar by introducing epoxy resin. This successfully resolved the issue of poor bonding between the continuous glass fiber textile and mortar interface, and promoted effective stress transfer between the two materials. The GTRM composites with an interfacial gradient structure exhibit excellent mechanical properties, including a tensile strength of 8 MPa and an interfacial shear force exceeding 27 KN. In addition, digital image correlation (DIC) was utilized to investigate the growth and development of cracks in GTRM composites, and the failure mechanism of tensile and interfacial shear tests was analyzed. Finally, the externally bonded GTRM composites were subjected to a three-point bending test, which demonstrated a significant improvement in the flexural strength and crack resistance of concrete beams.