\documentclass[aspectratio=169]{beamer}
\usepackage{ctex, hyperref}
\usepackage[T1]{fontenc}
% A SISU beamer based on THU beamer.
% other packages
\usepackage{latexsym,amsmath,xcolor,multicol,booktabs,calligra}
\usepackage{graphicx,pstricks,listings,stackengine}
\renewcommand{\figurename}{Figure.}
\renewcommand{\tablename}{Table.}
\author{Weiye}
\title{SISU Beamer Theme}
\subtitle{subtitle}
\institute{Shanghai International Studies University}
\date{date}
\usepackage{sisu}
% defs
\def\cmd#1{\texttt{\color{red}\footnotesize $\backslash$#1}}
\def\env#1{\texttt{\color{blue}\footnotesize #1}}
\definecolor{deepblue}{rgb}{0,0,0.5}
\definecolor{deepred}{rgb}{0.6,0,0}
\definecolor{deepgreen}{rgb}{0,0.5,0}
\definecolor{halfgray}{gray}{0.55}
\lstset{
basicstyle=\ttfamily\small,
keywordstyle=\bfseries\color{deepblue},
emphstyle=\ttfamily\color{deepred}, % Custom highlighting style
stringstyle=\color{deepgreen},
numbers=left,
numberstyle=\small\color{halfgray},
rulesepcolor=\color{red!20!green!20!blue!20},
frame=shadowbox,
}
\begin{document}
\kaishu
\begin{frame}
\titlepage
\begin{figure}[htpb]
\begin{center}
\includegraphics[width=0.15\linewidth]{pic/SISU.png}
\end{center}
\end{figure}
\end{frame}
\begin{frame}
\tableofcontents[sectionstyle=show,subsectionstyle=show/shaded/hide,subsubsectionstyle=show/shaded/hide]
\end{frame}
\section{Introduction}
\subsection{Backgrounds}
\begin{frame}{backgrounds}
...
\end{frame}
\section{References}
\begin{frame}[allowframebreaks]
\bibliography{ref}
\bibliographystyle{alpha}
% adjust the fonts if there are too many references：
% \tiny\bibliographystyle{alpha}
\end{frame}
\begin{frame}
\begin{center}
{\Huge\calligra Thanks!}
\end{center}
\end{frame}
\end{document}
