Abstract: This paper focuses on a quintessential instance of folk architecture, the Guanyin Temple in Luojiaqu Village. It offers an interpretation of the timber-structure design of its main hall from three distinct perspectives, drawing on site measurements. Regarding dimensional design, after mitigating the influence of truss deformation, it puts forward a set of hypotheses consisting of concise and adaptable integer dimensions. At the mortise-and-tenon level, the paper selects three typical structural nodes: the inter-rafter connection, the front end of through beams, and the concealed tail of angled cantilevers, to dissect the internal joints and deduce the design intentions. As for the component shapes of brackets, it identifies two craftsmanship clues and made comparisons between the Guanyin Temple and five related surrounding cases, resonating with the “Fenzhou Carpenter” documented in inscriptions. Overall, the design of the main hall of the Guanyin Temple exhibits far less regulation. Its carpentry logic and aesthetic preferences demonstrate substantial differences from those of contemporary buildings in the official style.