  MAXI J1816-195 is a newly discovered accreting millisecond pulsar with
prolific thermonuclear bursts, detected during its outburst in 2022 June by
Insight-HXMT and NICER. During the outburst, Insight-HXMT detected 73 bursts in
its peak and decay phase, serving as a prolific burst system found in the
accreting millisecond pulsars. By analyzing one burst which was simultaneously
detected by Insight-HXMT and NICER, we find a mild deviation from the
conventional blackbody model. By stacking the Insight-HXMT lightcurves of 66
bursts which have similar profiles and intensities, a hard X-ray shortage is
detected with a significance of 15.7 sigma in 30-100 keV. The shortage is about
30% of the persistent flux, which is low compared with other bursters. The
shortage fraction is
  energy-dependent: larger in a higher energy band. These findings make the
newly discovered millisecond MAXI J1816-195 a rather peculiar system compared
with other millisecond pulsars and atoll bursters. In addition, based on the
brightest burst, we derive an upper limit of the distance as 6.3 kpc, and
therefore estimate the upper limit of the inner disc radius of the accretion
disc to be~ 40 km. Assuming the radius as the magnetospheric radius, the
derived magnetic field strength is about 7.1*10^8 G.
