目前知识问答社区繁荣发展，但也面临着用户流失、知识增长缓慢、知识质量难以保证的问题，并由此导致社区内的知识交流效果不佳。理解知识交流效果的影响机制能够帮助个体充分利用知识问答社区实现高质量知识交流，同时为知识问答社区提供持续发展的路径。为此，文章基于数字资本理论视角构建了组态分析理论模型，采用定性比较分析方法，探讨数字资本与社会资本、文化资本和经济资本的组合效应。结果表明，知识问答社区的知识交流效果与其前因条件之间存在因果复杂性：就感知贡献而言，社会资本和文化资本的组合是提升感知贡献的核心条件，但数字资本可弥补其中社会资本或文化资本的缺失；就感知学习而言，数字资本、社会资本和经济资本是提升感知学习的核心条件。

At present, knowledge Q&A communities are flourishing and developing. However, they are also grappling with issues such as user attrition, sluggish knowledge growth, and challenges in ensuring the quality of knowledge shared, which may lead to poor knowledge exchange in the community. Understanding the influence mechanism of knowledge exchange effect can help individuals make full use of knowledge Q&A communities to realize high-quality knowledge exchange, and at the same time provide a path for sustainable development of knowledge Q&A communities. To this end，based on the perspective of digital capital theory, this paper constructs a theoretical model of configuration analysis, and discusses the combined effects of digital capital, social capital, cultural capital and economic capital by QCA. The results show that there is causal complexity between the effect of knowledge exchange and its antecedents: the combination of social capital and cultural capital is the core condition to enhance perceived contribution, but digital capital can make up for the absent of one of them; as far as perceived learning is concerned, digital capital, social capital and economic capital are the core conditions.