diff --git a/doc/example/thesis.tex b/doc/example/thesis.tex
index 30bc89d..8e6c261 100644
--- a/doc/example/thesis.tex
+++ b/doc/example/thesis.tex
@@ -42,8 +42,9 @@
 	cauthor = {某某}, eauthor = {Test}, date = {某年某月},
 	studentid = {0123456789}, school = {某某学院},
 	cmajor = {某某专业}, emajor = {Some Major},
-	direction = {某某方向},
-	cmentor = {某某教授}, ementor = {Prof.\ Somebody},
+	direction = {某某方向}, mentorlines = {2},
+	cmentor = {某甲教授\\某乙教授},
+	ementor = {Prof.\ Somebody and Prof.\ Someone},
 	ckeywords = {其一，其二},
 	ekeywords = {First, Second},
 	% 以下两项无双盲评审需求的用户可保持原状。
diff --git a/doc/readme/chap/pkuthss-chap2.tex b/doc/readme/chap/pkuthss-chap2.tex
index 5d2f911..bdc6af3 100644
--- a/doc/readme/chap/pkuthss-chap2.tex
+++ b/doc/readme/chap/pkuthss-chap2.tex
@@ -207,6 +207,7 @@
 		出于兼容性的考虑，如果 \texttt{\string\thesiscover} 为空，
 		那么封面将显示 \texttt{\string\cthesisname}。%
 	}。
+	\item \texttt{\bfseries\string\mentorlines}：封面“导师”部分的行数。
 	\item \texttt{\bfseries\string\cabstractname}：摘要的中文标题。
 	\item \texttt{\bfseries\string\eabstractname}：摘要的西文标题。
 \end{itemize}
@@ -353,20 +354,7 @@ $TEXMFDIST/tex/latex/pkuthss/
 一个常见的需求是封面中部分内容（特别是论文的标题、专业和研究方向）太长，
 超出了在预设的空间。
 此时，用户可以修改 \verb|pkuthss.cls| 里 \verb|\maketitle| 定义中
-\verb|\thss@int@fillinblank| 宏的参数来改变
-带下划线的空白的行数和行宽，其语法为：
-\begin{Verbatim}
-\thss@int@fillinblank{行数}{行宽}{内容}
-\end{Verbatim}
-例如，如果“研究方向”一栏需要两行的空白，
-可以将 \verb|pkuthss.cls| 里的
-\begin{Verbatim}
-\thss@int@fillinblank{1}{\thss@tmp@len}{\kaishu\@direction}
-\end{Verbatim}
-改为
-\begin{Verbatim}
-\thss@int@fillinblank{2}{\thss@tmp@len}{\kaishu\@direction}
-\end{Verbatim}
-当然，为了美观，可以将多于一行的部分移到封面中作者信息部分的最下方。
+\verb|\thss@int@fillinblank| 宏的参数来改变带下划线的空白的行数和行宽，
+具体方法可以参考该文件中和 \verb|\mentorlines| 相关的代码。
 
 % vim:ts=4:sw=4
diff --git a/doc/readme/pkuthss.tex b/doc/readme/pkuthss.tex
index 8305720..365efa6 100644
--- a/doc/readme/pkuthss.tex
+++ b/doc/readme/pkuthss.tex
@@ -63,8 +63,9 @@
 	date = {\zhdigits{2021}年\zhnumber{3}月},
 	studentid = {00910???}, school = {化学与分子工程学院},
 	cmajor = {应用化学}, emajor = {Applied Chemistry},
-	direction = {据说 Casper 自己也不知道},
-	cmentor = {XX 教授}, ementor = {Prof.\ XX},
+	direction = {据说 Casper 自己也不知道}, mentorlines = {2},
+	cmentor = {XX 教授\\YY 教授},
+	ementor = {Prof.\ XX and Prof.\ YY},
 	ckeywords = {\hologo{LaTeX}，排版，文档类，\CTeX{}},
 	ekeywords = {\hologo{LaTeX}, Typesetting, Document class, \CTeX{}},
 	blindid = {???01900}, discipline = {化学}
diff --git a/tex/pkuthss.cls b/tex/pkuthss.cls
index 60efd68..6ee4e69 100644
--- a/tex/pkuthss.cls
+++ b/tex/pkuthss.cls
@@ -235,6 +235,7 @@
 \thss@int@infoitemb{cthesisname}
 \thss@int@infoitemb{ethesisname}
 \thss@int@infoitemb{thesiscover}
+\thss@int@infoitemb{mentorlines}
 \thss@int@infoitemb{cabstractname}
 \thss@int@infoitemb{eabstractname}
 % Set up document information using the `key = value' grammar.
@@ -381,7 +382,8 @@
 				{\bfseries\label@direction}	&
 				\thss@int@fillinblank{1}{\thss@tmp@len}{\fangsong\@direction}	\\
 				{\bfseries\label@cmentor}		&
-				\thss@int@fillinblank{1}{\thss@tmp@len}{\fangsong\@cmentor}		\\
+				\thss@int@fillinblank{\mentorlines}%
+					{\thss@tmp@len}{\fangsong\@cmentor}	\\
 			\end{tabular}%
 		}
 		\vfill
diff --git a/tex/pkuthss.def b/tex/pkuthss.def
index 4042a01..9450851 100644
--- a/tex/pkuthss.def
+++ b/tex/pkuthss.def
@@ -1,6 +1,7 @@
 % Peking University dissertation document class
 %
-% Copyright (c) 2021 Casper Ti. Vector
+% Copyright (c) 2008-2009 solvethis
+% Copyright (c) 2010-2013,2015,2021 Casper Ti. Vector
 %
 % This work may be distributed and/or modified under the conditions of the
 % LaTeX Project Public License, either version 1.3 of this license or (at
@@ -28,6 +29,7 @@
 \def\euniversity{Peking University}
 \def\ethesisname{Doctor Thesis}
 \def\thesiscover{}
+\def\mentorlines{1}
 \def\eabstractname{ABSTRACT}
 
 \ifthss@opt@ugly