  We present long-term, multi-color photometric monitoring and spectroscopic
observations of the short-period M-type eclipsing binary BX Tri. Six flare
events were recorded in 4 years from 2014 to 2017. Three of them were detected
on one night within an orbital cycle. The strongest one was identified on
December 23, 2014. With the amplitudes of $\Delta$B=0.48 mag, $\Delta$V=0.28
mag, $\Delta$R=0.10 mag, $\Delta$I=0.02 mag, the total energy due to the flare
event was measured to be 4.08 ($\pm$0.24) $\times$$10^{34}$ erg, exceeding the
superflare level ($10^{34}$). Based on the observations, the evolutionary
status of the binary system as well as the long-term orbital period changes
were analyzed. It reveals that BX Tri is probably a semi-detached system with
the primary component filling its Roche lobe. The extremely high occurrence of
flare events of the binary could be related to the rapid mass transfer between
components.
