Let $H=(V,F)$ be a simple hypergraph without loops. $H$ is called linear if
$|f\cap g|\le 1$ for any $f,g\in F$ with $f\not=g$. The $2$-section of $H$,
denoted by $[H]_2$, is a graph with $V([H]_2)=V$ and for any $ u,v\in
V([H]_2)$, $uv\in E([H]_2)$ if and only if there is $ f\in F$ such that $u,v\in
f$. The treewidth of a graph is an important invariant in structural and
algorithmic graph theory. In this paper, we consider the treewidth of the
$2$-section of a linear hypergraph. We will use the minimum degree, maximum
degree, anti-rank and average rank of a linear hypergraph to determine the
upper and lower bounds of the treewidth of its $2$-section. Since for any graph
$G$, there is a linear hypergraph $H$ such that $[H]_2\cong G$, we provide a
method to estimate the bound of treewidth of graph by the parameters of the
hypergraph.