本文以会话分析和互动语言学为理论框架，基于电视谈话节目《圆桌派》中的自然口语语料，从话语结构和模态资源两个角度考察合作共建的形式，从主动型和被动型两个角度分析合作共建的功能，并探讨形式与功能之间的对应关系。研究发现：单句合作共建在话语结构中出现频率最高，多模态合作共建占主导地位；言语回应是最主要的功能，体现了合作共建增强会话互动性的本质属性。

This study adopts conversation analysis and interactional linguistics as its theoretical framework, drawing on natural spoken language data from the Chinese talk show Round Table. It examines the forms of co-construction from two perspectives—discourse structure and modal resources—analyzes the functions of co-construction from two angles—initiator-led and responder-led types—and explores the correspondence between form and function. The findings reveal that single-sentence co-construction occurs most frequently among discourse structures, and multimodal co-construction predominates overall. Verbal response emerges as the most prominent function, reflecting the essential nature of co-construction in enhancing interactional engagement in conversation.