This study takes Tao Tao Ju as the case study, and applies the assemblage theory to reveal the process and mechanism underlying the longevity of time-honored brands. The findings are as follows：in the cross-level connection and collaboration of time-honored brands, brand managers at the meso-level identify “institutional, material and spiritual culture” windows, and then adopt the assemblage strategies of “deterritorialization，territorialization and reterritorialization” to achieve a dynamic process of legitimacy acquisition, consolidation, and transition. Its emergent mechanism is that institutional culture drives structural alignment to obtain moral legitimacy, material culture drives sensory alignment to obtain pragmatic legitimacy, and spiritual culture drives emotional alignment to obtain cognitive legitimacy. The spiral interaction among the three alignments balances the continuity and change of time-honored brands, thereby contributing to their longevity.