Intramolecular　noncovalent　interaction　(INCI),　a　crucial　strategy　for　effectively　enhancing　molecular　planarity　and　extending　pi-electron　delocalization　in　organic　semiconductors　(OSCs),　has　played　an　increasingly　important　role　in　optoelectronic　applications.　However,　though　the　INCI　formation　is　regularly　considered　to　improve　the　device　performance　by　literature,　there　is　no　feasible　approach　to　directly　and　reliably　characterizing　its　formation　in　practical-OSC　films　thus　far.　Here　in　this　study,　by　theoretical　analysis　and　calculation,　the　generation　of　INCIs　in　OSCs　is　found,　normally　consisting　of　relatively　heavy　elements,　such　as　OSe,　OS,　NS　interactions,　etc.,　can　induce　enhanced　strength　of　spin-orbit　coupling,　the　primary　factor　dominating　spin　lifetime　in　OSCs.　Based　on　this　newly　discovered　theory,　spin　lifetime　is　creatively　employed　as　a　probe　for　sensitively　detecting　INCIs　in　OSC　films　via　spin　valves　or　field-induced　electron　paramagnetic　resonance,　respectively.　This　study　will　highly　promote　academic　and　applicable　developments　of　the　cross-cutting　frontier　research　field　between　organic　spintronics　and　electronics.