Utilizing the political concept of “rally-around-the-flag”, this study takes Jiuzhai Valley as a case to construct a framework of host-guest emotional solidarity and examines the dynamics of such solidarity after an earthquake and the COVID-19 pandemic. Thematic and sentiment analyses are applied to interpret Sina Weibo data and the narratives derived from residents’ interviews as a form of triangulation. Results show that under crisis: (1) host-guest emotional solidarity includes shared beliefs, shared emotions, and interactive behaviors; (2) the short-term rally effect is emotion-driven and depends on “we-ness” relationships, emotional empathy, and place identity; (3) the long-term rally effect is value-driven and emerges when host-guest emotional empathy develops into value resonance through resource integration and relationship reconstruction. The results have implications for emotional solidarity theory and destination recovery in times of crisis.