  Using wavelet analysis and power density spectrum, we investigate two
transient quasi-periodic oscillations (QPOs) observed in MAXI J1535$-$571
observed with Insight-HXMT. The transient QPOs have a centroid frequency of
$\sim 10$ Hz with a FWHM $\sim 0.6$ Hz and an rms amplitude $\sim 14\%$. Energy
spectra of QPO and non-QPO regimes are also separated and analyzed, and the
spectra become softer with higher $E_{cut}$ in the non-QPO regime compared to
the QPO regime. Our results suggest that the transient QPOs detected in MJD
58016 and 58017 are still the type-C QPO, and the source remains in its HIMS.
The duration of all type-C QPO signals based on wavelet is positively
correlated with the mean count rate above $\sim 10$ keV, implying appearance of
QPOs in different time scales should be coupled with the corona. The transient
QPO properties could be related to the jet or flares, perhaps the partial
ejection of the corona is responsible for the disappearance of the type-C QPO.

High Energy Astrophysical Phenomena;Solar and Stellar Astrophysics