随着现代信息技术的发展，文字、图像、声音等多模态符号元素对构建完整的话语意义起着越来越重要的作用。“讲好中国故事, 传播好中国声音”的外宣工作对新时代加强中国国际传播能力建设至关重要。维和宣传片《为和平出征》集多种模态于一体，讲述了中国维和故事及和平外交政策，展现了真实、立体、全面的负责任大国形象。多模态话语分析虽然在理论和应用上取得了显著成就，但在研究方法和范围上亟待完善。例如，鲜有动态语篇研究及多模态话语分析与其他领域的跨学科融合研究。

笔者探索总结出多模态话语分析理论和经典传播学理论拉斯韦尔5W模式之间的共通性，实现跨学科融合研究。具体来讲，本文以张德禄动态多模态话语分析综合框架、韩礼德的系统功能语法、克雷斯和勒文的视觉语法、勒文的听觉语法和拉斯韦尔5W模式为理论基础，采用定性和定量相结合的研究方法，构建出全新的分析框架，旨在探析维和宣传片《为和平出征》中文字、图像、声音等模态的意义建构机制、不同模态之间的关系以及宣传片的整体传播效果。

本文研究结论如下：(a) 文字模态意义建构。概念意义上，该片多用及物性物质过程展现中国和平外交理念和中国维和军人的卓越贡献。人际意义上，该片陈述语气所占比例较高，情态助词以中低情态值为主，旨在与观众建立起平等的关系。语篇意义上，该片多用非标记主位，以简单线性模式推进故事叙述；(b) 视觉模态意义建构。再现意义上，该片多用动作过程、反应过程和象征过程，突出和平主题。互动意义上，该片以提供类行为为主，远近镜头交替，注重气氛渲染和情感调动。构图意义上，该片运用前景化、中心化等不同凸显方式实现意义的整体建构；(c) 声音模态意义建构。多数情况下话外音被置于前景，时而穿插画中人物的真实声音，增强现场感。背景音乐基本根据文字和图像模态加以调整，声音距离处于公共距离水平，声音的音质水平总体较高；(d) 不同模态间的关系。该片以互补性强化关系和非互补性强化关系为主，前者突出文字模态的主导作用，后者强调各模态在整体意义建构中的不可或缺性；(e) 传播效果是以下四个方面综合作用的结果。传播主体上，各大主流媒体促进了社会主流文化价值的广泛有效传播。传播内容上，该片运用情理结合的传播技巧，全面讲述中国维和故事及共建人类命运共同体的中国方案。传播渠道上，该片强调借助多样化的外部新媒体传播平台和丰富的内在表达符号。受众上，该片主要受众为主流媒体和青年朋友，他们是当下推动中国文化传播的主要群体。本研究创新多模态话语分析研究视角，增进受众对中国蓝盔和中国和平发展理念的认识，推动外宣工作的开展。

With the development of modern information technology, multimodal symbolic elements such as texts, images, and sounds play an increasingly important role in constructing a complete discourse meaning. The external publicity work of "telling China's stories well and conveying China's voice well" is crucial for China's international communication capacity building in the new era. The peacekeeping promotional video For Peace integrates multiple modes, telling China's peacekeeping stories and foreign policy of peace and presenting a true, multi-dimensional, and panoramic view of a major responsible country. Although multimodal discourse analysis has made remarkable achievements in theory and application, its research method and scope need to be improved. For example, there are few studies on dynamic discourses and interdisciplinary integration of multimodal discourse analysis with other disciplines.

The author explores and summarizes the commonalities between multimodal discourse analysis theory and Lasswell's 5W Model, a classical communication theory, to realize interdisciplinary research. Specifically, according to Zhang Delu's synthetic framework for dynamic multimodal discourse analysis, Halliday's Systematical Functional Grammar, Kress and van Leeuwen's Visual Grammar, van Leeuwen's Aural Grammar, and Lasswell's 5W Model, this thesis constructs a new analytical framework to explore the meaning construction mechanisms of the verbal, visual, and auditory modes, relationships among different modes and the overall communication effect of the peacekeeping promotional video For Peace by combining qualitative and quantitative research methods.

The research conclusions of the thesis are as follows: (a) meaning construction of the verbal mode. For the ideational meaning, the video mainly uses transitive material processes to present China's diplomatic ideas of peace and the outstanding contributions made by Chinese peacekeepers. For the interpersonal meaning, the declaratives have a relatively larger proportion. Modal operators are dominated by low and median modal values, aiming to establish an equal relationship with the audience. For textual meaning, the video mainly uses unmarked themes to promote the narration of stories in a simple linear mode; (b) meaning construction of the visual mode. For representation meaning, the promotional video mainly uses action, reactional, and symbolic processes to highlight the theme of peace. For interactive meaning, the video is dominated by offer acts, and it alternates long and short shots, paying attention to rendering the atmosphere and arousing emotions. For compositional meaning, the overall meaning construction is realized through different ways of salience such as foregrounding and centralization; (c) meaning construction of the auditory mode. The voice-over is placed in the foreground in most cases, and the video is occasionally interspersed with the authentic voice of the represented participants to enhance the sense of presence. The background music is adjusted to the verbal and visual modes, the aural distance is mainly at the public distance, and the sound is generally of high quality; (d) the relationship among different modes. The video primarily uses complementary reinforcing relationships and complementary non-reinforcing relationships. The former emphasizes the dominant role of the verbal mode, and the latter focuses on the indispensability of each mode in overall meaning construction; (e) The communication effect is the composite effect of the following four aspects. For communication subjects, major mainstream media promote the widespread and effective communication of mainstream social and cultural values. Regarding communication contents, the video adopts the communication skill of combining facts and emotion to fully tell China's peacekeeping stories and China's plan of building a community with a shared future for mankind. In terms of communication channels, the video emphasizes the use of diversified external new media communication platforms and rich internal symbolic expressions. As for the audience, the main audience of the video is mainstream media and the youth, who are the primary groups promoting the communication of Chinese culture. The study innovates the research perspective for multimodal discourse analysis, promotes the audience’s understanding of China's Blue Helmets and Chinese ideas of peaceful development, and advances the development of external publicity work.