  The dynamical and radiative properties of the quiescent state (X-ray
luminosity $<10^{34}\ {\rm erg s^{-1} cm^{-2}}$) of black hole X-ray transients
(BHXTs) remains unclear, mainly because of low-luminosity and poor data
quantity. We demonstrate that, the simultaneous multi-wavelength (including
radio, optical, ultraviolet and X-ray bands) spectrum of V404 Cyg in its bright
quiescent state can be well described by the radiation from the companion star
and more importantly, the compact jet. Neither the outer thin disc nor the
inner hot accretion flow is important in the total spectrum. Together with
several additional recent findings, i.e. the power-law X-ray spectrum and the
constant X-ray spectral shape (or constant photon index) in contrast to the
dramatic change in the X-ray luminosity, we argue the quiescent state spectrum
of BHXTs is actually jet-dominated. Observational features consistent with this
jet model are also discussed as supporting evidences.
