  The millimeter bump, as found in high-resolution multi-waveband observations
of M87, most possibly comes from the synchrotron emission of thermal electrons
in advection dominated accretion flow(ADAF). It is possible to constrain the
accretion rate near the horizon if both the nuclear millimeter emission and its
polarization are produced by the hot plasma in the accretion flow. The jet
power of M87 has been extensively explored, which is around $8_{\rm
-3}^{+7}\times10^{42} {\rm erg/s}$ based on the analysis of the X-ray cavity.
The black hole(BH) spin can be estimated if the jet power and the accretion
rate near the horizon are known. We model the multi-wavelength spectral energy
distribution (SED) of M87 with a coupled ADAF-jet model surrounding a Kerr BH,
where the full set of relativistic hydrodynamical equations of the ADAF are
solved. The hybrid jet formation model, as a variant of Blandford-Znajek model,
is used to model the jet power. We find that the SMBH should be fast rotating
with a dimensionless spin parameter $a_{*}\simeq0.98_{\rm -0.02}^{+0.012}$.
