> For the complete documentation index, see [llms.txt](https://overleaf-pro.ayaka.space/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://overleaf-pro.ayaka.space/latex/zh-cn/zhi-shi-ku/127-set-main-document.md).

# 设置主文档

Overleaf 中的主文档是 LaTeX 将被告知首先编译的文件。它是项目的主文件，所有其他部分（类、宏包、章节等）都会被输入到其中。当没有手动设置时，Overleaf 会在项目中选择一个包含 **`\documentclass[...]{...}`** 命令的文档。因此，如果你有一个单独的导言文件，最好不要把 **`\documentclass[...]{...}`** 命令包含在导言文件中，而应放在主文档的开头。如果不这样做，只有导言部分会被编译。要在项目中设置主文档，只需点击左上角的菜单：

![左侧菜单.PNG](/files/92774bcd1bff9309617ff93edcc3ec422f24a57d)

并转到 **主文档**:

![Maindocument.PNG](/files/d76eed428e22902fb37936d5b946a4ec8006a8f5)

参见 [这里](/latex/zh-cn/wen-dang-jie-gou/07-management-in-a-large-project.md) 以了解更多关于在 LaTeX 中管理大型项目的信息。

## 在同一项目中编译多个文档

为了让你能够快速编译同一项目中的不同文档，Overleaf 会将编辑器中当前打开的文件作为主文档来编译，只要它包含 **`\documentclass[...]{...}`** 命令。这对于使用 [**`subfiles`** 宏包](/latex/zh-cn/wen-dang-jie-gou/08-multi-file-latex-projects.md#the-subfiles-package).

## 主文件选择问题

主文件应始终位于根目录中（不在任何文件夹内），以确保所有编译步骤都在正确的目录中运行，并确保所需的辅助文件可用，例如在 [添加索引](/latex/zh-cn/wen-dang-jie-gou/04-indices.md)时。有关重新组织项目以在 Overleaf 上编译的一些提示，参见 [这里](/latex/zh-cn/wen-da/77-my-main-file-is-in-a-subfolder-but-this-is-not-allowed-on-overleaf.-but-i-don-t-want-to-change-my.md).

如果所选的主文件位于某个文件夹中，而根目录中有一个同名文件，那么将编译根目录中的该同名文件，而不是所选文件。例如，若 `version1/main.tex` 被设为主文件，但 `main.tex` 也在项目中， `main.tex` 将被编译。此问题是由于 Overleaf 上 Latexmk 的运行方式所致。为避免由此带来的问题，请给任何你希望在 Overleaf 上编译的文件起一个唯一的名称。


---

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