  The dominating superconducting pairing symmetry of the kagome-lattice Hubbard
model is investigated using the determinant quantum Monte Carlo method. The
superconducting instability occurs when doping the correlated insulators formed
by the Hubbard interaction near the Dirac filling, and the superconducting
state exhibits an electron-hole asymmetry. Among the pairing symmetries
allowed, we demonstrate that the dominating channel is d-wave in the hole-doped
case. This opens the possibility of condensation into an unconventional
$d_{x^2-y^2}+id_{xy}$ phase, which is characterized by an integer topological
invariant and gapless edge states. In contrast, the $s^*$-wave channel, which
has no change of sign in the pairing function, is favored by electron doping.
We further find the dominating $s^*$-wave pairing persists up to the Van Hove
singularity. The results are closely related to the recent experimental
observations in kagome compounds AV3Sb5(A: K, Rb, Cs), and provide insight into
the pairing mechanism of their superconducting states.
