A new naphthalene diimides extended‐pillar[6]arene 1 with a large cavity and rich host‐guest complexation properties was synthesized in high yield. It can not only form 1:2 complexes with large size polycyclic aromatic hydrocarbons but also form 1:1:1 ternary complex with perylene and 2,7‐diazapyrenium. Moreover, the supramolecular exchange reaction from a 1:2 host‐guest complex 1•(G3)2 formed by 1 and perylene to a 1:1:1 ternary complex 1•G3•G5 formed by 1 with perylene and 2,7‐diazapyrenium salt was also investigated by 1H NMR experiments as well as theoretically calculations.