Abstract: To investigate the influence of key parameters on the out-of-plane tensile properties of needle-punched and stitched composites, four types of needle-punched and stitched composites with different process parameters were prepared and the out-of-plane tensile properties and damage evolution mechanisms were studied. The results indicate that the out-of-plane tensile strength significantly increases as the stitching interval decreases. Specifically, the stitch spacing were 8 mm×8 mm, 6 mm×6 mm, and 4 mm×4 mm, the out-of-plane tensile strength increased by 28%, 41.14%, and 58.29%, respectively. However, the effect of reducing the stitch spacing on improving the out-of-plane tensile strength shows a diminishing trend. During the out-of-plane tensile process, areas with larger strain initially appear at the stitching positions. As the load increases until the stitching breaks, interlaminar cracking occurs in the composite. Reducing the stitch spacing has a significant effect on strain concentration areas, resulting in a more uniform strain distribution during the tensile process. The failure modes of out-of-plane tensile for needle-punched and stitched composites mainly include stitches breakage and pull-out, cracking between the base fabric layers, and matrix cracking. Reducing the stitch spacing causes the fracture surface of the out-of-plane tensile experiment to become rougher, with cracks propagating along different layers and multiple unit-layers experiencing damage.