  We extend our research on the energy flux and waveform characteristics of
gravitational waves generated by merging nonspinning binary black holes through
self-consistent effective one-body theory \cite{L2023} to include binary
systems with slowly spinning black holes. Initially, we decompose the equation
for the null tetrad component of the gravitationally perturbed Weyl tensor
$\psi^B_{4}$ into radial and angular parts, leveraging the second-order
approximation of the rotation parameter $a$. Subsequently, we derive an
analytical solution for the radial equation and observe that our results are
contingent upon the parameters $a_2$, $a_3$ and $a$, which represent the
second- and third-order correction parameters, respectively. Ultimately, we
calculate the energy flux, the radiation-reaction force and the waveform for
the ``plus" and ``cross" modes of the gravitational waves generated by merging
slowly spinning binary black holes.
