  The Zero Degree Calorimeter (ZDC) plays a crucial role in determining
centrality at the Cooling-Storage-Ring External-target Experiment (CEE) in the
Heavy Ion Research Facility in Lanzhou (HIRFL). A Boosted Decision Trees (BDT)
multi-classification algorithm is employed to classify the centrality of the
collision events based on the raw features from ZDC such as the number of fired
channels and deposited energy. The data from simulated $\rm ^{238}U$ + $\rm
^{238}U$ collisions at 500 $\rm MeV/u$, generated by the IQMD event generator
and subsequently modeled through the GEANT4 package, is employed to train and
test the BDT model. The results showed the high accuracy of the
multi-classification model adopted in ZDC for centrality determination, which
is robust against variations in different factors of detector geometry and
response. The study demonstrates a good performance of the CEE-ZDC for
determining the centrality in nucleus-nucleus collisions.
