  In this paper, we simulate the gamma-ray bursts (GRBs) prompt emission light
curve, spectrum and $E_p$ evolution patterns within the framework of the
Internal-Collision-induced MAgnetic Reconnection and Turbulence (ICMART) model.
We show that this model can produce a Band shape spectrum, whose parameters
($E_p$, $\alpha$, $\beta$) could distribute in the typical distribution from
GRB observations, as long as the magnetic field and the electron acceleration
process in the emission region are under appropriate conditions. On the other
hand, we show that for one ICMART event, $E_p$ evolution is always a
hard-to-soft pattern. However, a GRB light curve is usually composed of
multiple ICMART events that are fundamentally driven by the erratic GRB central
engine activity. In this case, we find that if one individual broad pulse in
the GRB light curve is composed of multiple ICMART events, the overall $E_p$
evolution could be disguised as the intense-tracking pattern. Therefore, mixed
$E_p$ evolution patterns can coexist in the same burst, with a variety of
combined patterns. Our results support the ICMART model to be a competitive
model to explain the main properties of GRB prompt emission. The possible
challenges faced by the ICMART model are also discussed in details.
