首先引入宏包:\usepackage{array}
然后,在\begin{tabular}后面加上如{p{8cm} p{2.5cm}<{\centering}}的代码即可。
如:
\begin{table}[H]
\centering
\caption{Parameters in GA}\label{Para_GA}
\begin{tabular}{p{8cm} p{2.5cm}<{\centering}}
\toprule
123 & 456 \\
\midrule
ABC & abc \\
\bottomrule
\end{tabular}
\end{table}