Glass fiber tape reinforced polyethylene (GFTRP) pipes are widely used for the transportation of oil and high-pressure gas due to their good load-bearing capacity and environmental compatibility. Delamination defect is one of the most common defects of GFTRP pipes during manufacturing and service (Jones et al., “Delamination Growth in Polymer-Matrix Fibre Composites and the Use of Fracture Mechanics Data for Material Characterisation and Life Prediction,” Compos. Struct., 2017. 180, 316–333). This paper investigates the load-bearing capacity of GFTRP pipe with interlayer delamination defect in between glass fiber tapes, via a combined experimental and numerical method. In burst experiments, GFTRP pipes with layup of [±55 deg]12 were prepared with artificial delamination defects set in between sixth and seventh plies. In numerical model, progressive damage model and cohesive element method were used to analyze the failure of GFTRP pipe with interlayer delamination defect. Results showed that interlayer delamination defect would reduce the burst pressure of GFTRP pipes. Different defect widths and their axial locations had different reduction effects on burst pressure, and the predicted results from numerical model showed good consistency with experimental results. Ultimately, the influence of defect width and location on the burst pressure of GFTRP pipe was discussed in detail.