  The interstellar extinction law is important for interpreting observations
and inferring the properties of interstellar dust grains. Based on the 993
prism/CLEAR spectra from the James Webb Space Telescope (JWST), we investigate
$0.6-5.3\,{\rm \mu m}$ interstellar dust extinction law. We propose a pair
method to obtain the reddening curves based only on JWST observed spectra. Most
of the high extinction sources are toward the young star cluster Westerlund 2.
The infrared (IR) $1.0-5.3\,{\rm \mu m}$ reddening curves agree with the
power-law $A_\lambda \propto \lambda^{-\alpha}$ well. We determine an average
value of $\alpha=1.98\pm0.15$, which is consistent with the average value of
the Galaxy. We find that $\alpha$ may be variable and independent of $R_{\rm
V}$. With the derived $\alpha$, we convert the reddening curves into the
extinction curves and establish the non-parameterized $\alpha$-dependent
extinction curves in the wavelength range of $0.6-5.3\,{\rm \mu m}$. At
$\lambda<1\,{\rm \mu m}$, the derived extinction law is not well described by
the parameterized power-law type curve. Our non-parameterized
$\alpha$-dependent extinction curves are suitable for the extinction correction
of JWST-based photometry and spectra measurements at $0.6-5.3\,{\rm \mu m}$. We
also provide the extinction coefficients for the JWST NIRCam bandpasses with
different $\alpha$.
