  We calculate the jet power of the Blandford-Znajek (BZ) model and the hybrid
model based on the self-similar solution of advection-dominated accretion flows
(ADAFs). We study the formation mechanism of the jets of BL Lacs with known
redshifts detected by the Fermi satellite after 10 yr of data (4FGL-DR2). The
kinetic power of the jets of Fermi BL Lacs is estimated through radio
luminosity. The main results are as follows. (1) We find that the jet kinetic
power of about 72\% intermediate peak frequency BL Lacs (IBL) and 94\%
high-frequency peak BL Lacs (HBL) can be explained by the hybrid jet model
based on ADAFs surrounding Kerr black holes. However, the jet kinetic power of
about 74\% LBL cannot be explained by the BZ jet model or the hybrid model. (2)
The LBL has a higher accretion rate than IBL and HBL. About 14\% IBL and 62\%
HBL have pure optically thin ADAFs. However, 7\% LBL may have a hybrid
structure consisting of an standard thin disk (SS) plus optically thin ADAFs.
(3) After excluding the redshift dependence, there is a weak correlation
between the jet kinetic power and the accretion disk luminosity for Fermi BL
Lacs. (4) There is a significant correlation between inverse Compton luminosity
and synchrotron luminosity for Fermi BL Lacs. The slope of the relation between
inverse Compton luminosity and synchrotron luminosity for Fermi BL Lacs is
consistent with the synchrotron self-Compton (SSC) process. The result may
suggest that the high-energy components of Fermi BL Lacs are dominated by the
SSC process.
