Abstract: Needled/stitched multi-scale interlocking composites have excellent interlaminar properties and are increasingly used in aerospace thermal structure composites. However, the effect of stitch technology on double incision interlaminar shear (DNS) performance of needle composites remains unclear. Using quartz satin fabric and quartz twill half-cut fabric as materials, quartz fiber-reinforced resin-based needle/stitch multi-scale interlocking composites with three kinds of stitch pattern and four kinds of stitch fiber bundles were designed and prepared. The DNS performance of the composite was tested and analyzed. The internal structure of the fabric was characterized by micro-CT, and the fracture morphology of the sample was observed by scanning electron microscopy (SEM) to clarify the mechanism of interlayer strengthening. The DNS behavior of needled/stitched multi-scale interlocking composites was further investigated by cohesive zone model (CZM) and Abaqus software, and the ultimate failure strength was predicted. The results show that the introduction of stitch technology greatly improves the interlamellar properties of the composite, and the maximum failure load of DNS reaches 32.73 MPa, which is 86.46% higher than that of the needled composite. The main failure modes of multi-scale interlocking composite DNS are matrix cracking, brittle fracture and pulling out of fiber bundle. At the same time, the simulation results are in good agreement with the DNS experimental results of needled/stitched multi-scale interlocking composites, and the maximum error is less than 8%, which proves that the cohesion model established in this paper can effectively predict the interlaminar shear performance of needled/stitched multi-scale interlocking composites.