  In this article, we calculate the dressed quark propagator with the flat
bottom potential in the framework of the rain-bow Schwinger-Dyson equation,
which is determined by mean field approximation of the global colour model
lagrangian. The dressed quark propagator exhibits a dynamical symmetry breaking
phenomenon and gives a constituent quark mass about 392 MeV, which is close to
the value of commonly used constituent quark mass in the chiral quark model.
Then based on the dressed quark propagator, we calculate some properties of the
vacuum, such as quark condensate, mixed quark condensate $g_{s}<
0|\bar{q}G_{\mu\nu}\sigma^{\mu\nu}q|0>$, four quark condensate $<0|\bar{q}
\Gamma q\bar{q} \Gamma q |0>$, tensor, $\pi$ vacuum susceptibilities. The
numerical results are compatible with the values of other theoretical
approaches.
