Traditional interlayer fiber reinforced polymer (FRP) composites utilized in civil engineering are deficient in either the sufficient stiffness or ductility. For this, a study was conducted on the tensile behavior of interlayer hybrid FRP composites, which were composed of polypropylene (PP) and glass fabrics with an epoxy resin as the matrix and a central layer of glass fabric. This paper presents the design concept, failure mode, and constitutive model for glass/PP FRP composites. The experimental results indicate that the glass/PP FRP composites exhibit higher stiffness and ductile compared to traditional FRP composites, thereby demonstrating superior mechanical properties. Moreover, the finite element (FE) method was employed to identify all potential failure modes of glass/PP FRP composites, and it was concluded that only delamination failure mode is applicable in civil engineering. Based on the FE results, a failure mode map was generated for glass/PP FRP composites, which can facilitate rapid identification of its failure modes. To quantify the tensile behavior of these composites, a two-limit tensile constitutive model was developed. Considering that composites are typically designed for tension, the research presented in this paper can offer theoretical support for the implementation of glass/PP composites in civil engineering applications.