Pd NCs@COFs catalysts were synthesized using a facile synthesis procedure via in-situ method at room temperature. They were used as catalysts for cross-coupling reactions using the Heck reaction. The catalytic performance of Pd NCs@COFs nanocomposite showed complete conversion (100 %) with five mol.% of Pd NCs. The high conversion was observed for several aryl halides and vinyl derivatives. We expect these catalysts to be viable for synthesizing several more new organic compounds via cross-coupling reactions using Pd-based catalysts.