SwiftJ0243.6+6124, the first Galactic ultra-luminous X-ray pulsar, was observed during its 2017-2018 outburst with emph{AstroSat} at both sub- and super-Eddington levels of accretionwith X-ray luminosities of $L_{X}{sim}7{times}10^{37}$ and $6{times}10^{38}$$ergs^{-1}$, respectively.Our broadband timing and spectral observations show that X-ray pulsations at ${sim}9.85rm{s}$ have been detected up to 150keV when the source was accreting at the super-Eddington level.The pulse profiles are a strong function of both energy and source luminosity,showing a double-peaked profile with pulse fraction increasing from $sim$$10{%}$ at $1.65rm{keV}$ to 40--80$%$ at $70rm{keV}$.The continuum X-ray spectra are well-modeled with a high energy cut-off power law($Gamma$${sim}$0.6-0.7) and one or two blackbody components with temperatures of $sim$0.35$rm{keV}$ and $1.2rm{keV}$, depending on the accretion level.No iron line emission is observed at sub-Eddington level, while a broad emission feature at around 6.9keV is observed at the super-Eddington level, along with a blackbody radius($121-142rm{km}$) that indicates the presence of optically thick outflows.
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