  Shannon information entropy provides an effective tool to study the evolution
process in relativistic heavy-ion collisions. The time evolution process of
thermodynamic entropy $S_{\rm thermal}$, multiple entropy $S_{\rm mul}$, and
configuration entropy $S_{\rm conf}$ at RHIC is studied using the AMPT model to
generate central Au-Au collisions. By superimposing the three kinds of
information entropy, we can get a more complete information entropy of the
system to describe the physical information of the relativistic heavy ion
collision. The results show that the four stages of the time evolution process
of the system entropy $S$ seem to correspond to the four physical processes in
the relativistic heavy ion collision, indicating that the total entropy of the
system can reflect the physical information in the relativistic heavy ion
collision more accurately.
