Stellar tidal disruption events (TDEs) are not only a new tool to discover more massive black holes and to study their growth history, but also a test bed for black hole accretion physics and general relativity. The observed sample of TDE candidates has increased rapidly in recent 5 years. However, our understanding of TDE's multi-wavelength radiation signatures has not reached a consensus. In particular, the different temporal behaviours between optical / UV and X-rays for some TDEs have not been well explained. I will present some ongoing efforts to address the physical origins of their multi-wavelength light curves.