  The topcolor-assisted technicolor (TC2) model predicts several pseudo-scalars
called top-pions and at loop level they can induce the FCNC top quark decay
t->cgg which is extremely suppressed in the Standard Model (SM). We find that
in the allowed parameter space the TC2 model can greatly enhance such a FCNC
decay and push the branching ratio up to 10^{-3}, which is much larger than the
predictions in the SM (10^{-9}) and in the minimal supersymmetric model
(10^{-4}). We also compare the result with the two-body FCNC decay t-> cg and
find that the branching ratio of t-> cgg is slightly larger than t-> cg. Such
enhanced FCNC top quark decays may serve as a good probe of TC2 model at the
future top quark factory.
