\documentclass[a4paper]{article}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{wasysym}
\usepackage[labelfont=bf]{caption}
\usepackage[margin={1cm,1cm}]{geometry}
\usepackage{multicol,lipsum,graphicx,float}
\begin{document}
\begin{multicols*}{2}
\begin{figure}[!h]
\centering{\includegraphics[width=7cm]{fig3.png}}
\caption{
this is caption
}
\end{figure}
\end{multicols}