  The strong and electromagnetic corrections to $\rho-\omega$ mixing are
calculated using a SU(2) version of resonance chiral theory up to
next-to-leading orders in $1/N_C$ expansion, respectively. Up to our accuracy,
the effect of the momentum dependence of $\rho-\omega$ mixing is incorporated
due to the inclusion of loop contributions. We analyze the impact of
$\rho-\omega$ mixing on the pion vector form factor by performing numerical fit
to the data extracted from $e^+e^-\rightarrow \pi^+\pi^-$ and $\tau\rightarrow
\nu_{\tau}2\pi$, while the decay width of $\omega\rightarrow \pi^+\pi^-$ is
taken into account as a constraint. It is found that the momentum dependence is
significant in a good description of the experimental data. In addition, based
on the fitted values of the involved parameters, we analyze the decay width of
$\omega \rightarrow \pi^+\pi^-$, which turns out to be highly dominated by the
$\rho-\omega$ mixing effect.
