Latex 四级编号1.1.1.1设置

\subsubsubsection doesn't exist but, instead, you can use \paragraph and \subparagraph, which will generate something like 1.1.1.1 and 1.1.1.1.1. .

To include this in your table of contents, you have to declare \setcounter{tocdepth}{4} and \setcounter{secnumdepth}{4}. For subparagraph, use {5}.

There are 7 levels of sections (depending on the document)

-1     \part{part}

0     \chapter{chapter}

1     \section{section}

2     \subsection{subsection}

3     \subsubsection{subsubsection}

4     \paragraph{paragraph}

5     \subparagraph{subparagraph}

\part and \chapter are only available in report and book.