Understanding how tourists’ brand experiences impact their existential authenticity, and the role of existential authenticity in the formation mechanism of place attachment to the destination, are key issues for the marketing of a destination. The current study examines the relationship between tourists’ experience, existential authenticity, and place attachment, and the indirect effect of existential authenticity on the relationship between destination brand experience and place attachment from the oriental perspective against the slow tourism background. A self-administered survey was conducted at Yaxi town, the first international slow city in China. A total of 398 samples were analyzed using a two-step approach of the structural equation model (SEM). The findings show that destination brand experience partially impacts existential authenticity, and both the intrapersonal and interpersonal authenticity (the sub-dimensions of existential authenticity) significantly influence place attachment. Additionally, affective and behavioral experience indirectly influence place attachment through existential authenticity. Based on the conclusions, theoretical and practical recommendations are considered.