<p>Intangible cultural heritage (ICH) represents a fundamental element of human civilization and serves as a valuable resource for cultural tourism. However, the willingness and motivation of ICH practitioners—the key bearers of living heritage—to transmit their traditional knowledge remain relatively limited. Therefore, how to stimulate the intrinsic motivation of the inheritors’ inheritance behavior is the focus of this research.Grounded in the Motivation-Opportunity-Ability (MOA) framework, this study integrates grounded theory with partial least squares structural equation modelling to develop a comprehensive mechanism explaining how external opportunities influence practitioners’ inheritance behavior through internal motivational and capability factors. Drawing on a mixed-methods approach centered on practitioners of Oolong Tea Making Skills, the research findings indicate that: (1) Inheritance behavior is directly influenced by inheritance motivation, intrinsic capability, and external opportunity, following a sequential mediation pathway of “external opportunity → intrinsic capability → inheritance motivation → inheritance behavior.” (2) Local cultural vitality positively moderates the relationship between inheritance motivation and inheritance behavior, suggesting that a more vibrant local cultural environment strengthens the conversion of motivational intent into actual transmission practices. Distinct from prior studies, this research clarifies the intricate mechanisms underlying ICH practitioners’ behavioral engagement in heritage transmission and introduces local cultural vitality as a novel moderating factor, thereby advancing both the theoretical application of the MOA model and scholarly discourse on ICH sustainability. Practical recommendations are further provided to strengthen the intergenerational transmission capacity of ICH practitioners, offering actionable guidance for supporting the continuity of living cultural heritage.</p>