解决方案

结果如下：

源代码如下：

\documentclass{article}
% \usepackage[utf8]{ctex}
\usepackage{multirow}
\usepackage{graphicx}
\usepackage{booktabs}
\usepackage{caption}

\begin{document}

\captionsetup{font={large}}

\begin{table}[]
\centering
\resizebox{0.5\textwidth}{!}{
\begin{tabular}{@{}cc|c|ccc@{}}

\toprule
\multicolumn{2}{c|}{Model} & \multirow{2}{*}{Criterion} & \multicolumn{3}{c}{Index} \\  

\multicolumn{1}{c}{A} & B &  & A & B & \multicolumn{1}{c}{C} \\ \midrule

\multicolumn{1}{c|}{a} & b & 0 &  &  &  \\ \midrule

\multicolumn{1}{c|}{\multirow{3}{*}{a}} & b & 1 &  &  &  \\
\multicolumn{1}{c|}{} & b & 2 &  &  &  \\
\multicolumn{1}{c|}{} & b & 3 &  &  &  \\ \midrule

\multicolumn{1}{c|}{\multirow{3}{*}{a}} & b & 4 &  &  &  \\
\multicolumn{1}{c|}{} & b & 5 &  &  &  \\
\multicolumn{1}{c|}{} & b & 6 &  &  &  \\ 
\bottomrule

\end{tabular}%
}

\caption{Group01}
\label{tab:my-table}
\end{table}

\end{document}

实验在线网站：overleaf