Abstract: A cellular automata-based multi-line ship lock traffic flow model is developed for optimizing the operation performance of the lock. The model is designed for both straight approaching channel and curved approaching channel and integrated with lock chamber allocation rule, BL layout algorithm and the rules for lock chamber parrel running. The ship lock part and the channel part of the model are defined as the node and the path in the system respectively. The model is used to investigate the four-line ship lock of Changzhou hydraulic complex. The spatiotemporal distribution and the index of ship lock running optimization level are calculated and analyzed. The simulation shows that the optimization can decrease the up-going and down-going delay by 10.3% and 8.8% respectively and raise the running efficiency of lock chamber by 7.4% and 7.1% respectively.