1、两个子图横排

\begin{figure}[!t]
\centering
%\includegraphics[width=3in]{fig5}
\subfloat[subfig figure title]{
		\includegraphics[scale=0.5]{superd2}}
\subfloat[subfig figure title]{
		\includegraphics[scale=0.5]{superd2}}
\caption{title}
\label{fig_6}
\end{figure}

注：superd2为图片的文件名

2、两个子图竖排

\begin{figure}[!t]
\centering
%\includegraphics[width=3in]{fig5}
\subfloat[subfig figure title]{
		\includegraphics[scale=0.5]{superd2}}\\
\subfloat[subfig figure title]{
		\includegraphics[scale=0.5]{superd2}}
\caption{title}
\label{fig_6}
\end{figure}

3、四个子图排列

\begin{figure}[!t]
\centering
%\includegraphics[width=3in]{fig5}
\subfloat[subfig figure title]{
		\includegraphics[scale=0.5]{superd2}}
\subfloat[subfig figure title]{
		\includegraphics[scale=0.5]{superd2}}
\\
\subfloat[subfig figure title]{
		\includegraphics[scale=0.5]{superd2}}
\subfloat[subfig figure title]{
		\includegraphics[scale=0.5]{superd2}}
\caption{title}
\label{fig_6}
\end{figure}