  We hereby report the discovery of ATLAS17jrp as an extraordinary TDE in
star-forming galaxy SDSSJ162034.99+240726.5 in our recent sample of
mid-infrared outbursts in nearby galaxies. Its optical/UV light curves rise to
a peak luminosity $\sim1.06\times10^{44}\rm\,erg\,s^{-1}$ in about a month and
then decay as $\rm t^{-5/3}$ with a roughly constant temperature around
19000~K, and the optical spectra show a blue continuum and very broad Balmer
lines with FWHM$\sim$15000 km/s which gradually narrowed to 1400 km/s within 4
years, all agreeing well with other optical TDEs. A delayed and rapidly rising
X-ray flare with a peak luminosity $\rm \sim 1.27\times10^{43}\,erg\,s^{-1}$
was detected at $\rm \sim$ 170 days after the optical peak. The high MIR
luminosity of ATLAS17jrp ($\sim2\times10^{43} \rm\,erg\,s^{-1}$) has revealed a
distinctive dusty environment with covering factor as high as $\sim0.2$, that
is comparable with that of torus in active galactic nuclei but at least one
order of magnitude higher than normal optical TDEs. Therefore, ATLAS17jrp turns
out to be one of the rare unambiguous TDE found in star-forming galaxies and
its high dust covering factor implies that the dust extinction could play an
important role in the absence of optical TDEs in star-forming galaxies.
