To address the current challenges of corrosion susceptibility, fatigue vulnerability, and excessive outer diameter in fiber-reinforced thermoplastic pipes (RTPs) connection joints, this study designed a novel fusion-reinforced joint based on theoretical modeling. A methodology combining finite element simulations and burst testing is employed to systematically investigate the failure mechanisms of fusion-reinforced joints of RTPs under burst loading conditions. The progressive damage evaluation method based on the VUMAT subroutine was developed by combining the 3D Hashin failure criterion with the maximum stress criterion, and integrating residual stiffness modeling and cohesive zone modeling. Experimental and numerical results demonstrate that the ultimate failure mode is the failure of the adhesive layer and the fusion zone. The damage evolution process progresses through four distinct stages, namely the initial undamaged stage, the adhesive layer damage stage, the matrix damage stage, and the final catastrophic failure stage. The damage of the adhesive layer spreads from both ends of the joint towards the center, with insufficient shear strength of the adhesive interface identified as the primary contributing factor. Matrix damage in the RTPs reinforcement layer initially occurs adjacent to the joint interface and progressively extends to non-joint regions. The matrix damage in the joint area is influenced by the expansion law of the adhesive layer damage.