\documentclass[a4paper]{book}

\usepackage{fancyhdr}
\usepackage{xepersian}

\renewcommand{\headrule}{\rule{\textwidth}{1pt}\\[-3mm]\rule{\textwidth}{1pt}}

\pagestyle{fancy}
\begin{document}
\chapter{آ}

~\clearpage

\chapter{آ}

~\clearpage

\chapter{آ}

~\clearpage

\end{document}