Herein, we show a feasible protocol of nanohybrid shish kebab (NHSK) in isotactic polypropylene (iPP)/low density polyethylene (LDPE) blend, where iPP nanofibrils in situ generate during melt compounding followed by hot stretching, thus severing as shish to induce the kebabs of LDPE under extensional flow, therewith leading to greatly improved mechanical properties. Additionally, our work provides a novel understanding of extensional flow-induced interfacial crystallization. Through the comparison of LDPE lamellae epitaxially growing on iPP nanofibrils substrate under quiescent condition, some LDPE chains are oblique off the axis of iPP nanofibrils, indicating the unusual mechanism of flow-induced NHSK: (1) iPP nanofibrils induced epitaxial nucleation of LDPE chains; (2) formation of the transition zone mainly by intralamellar slips, fragmentation and reorientation; (3) perpendicularly growth of LDPE kebabs. Moreover, of particular significance is the methodology based on practical processing of extrusion in this work, making it promising to industrially achieve NHSK in polymer blend with advanced performance.