With the rapid development of China train control system (CTCS-3), stability and safety of the CTCS-3 have become the focus of the train industry. According to the CTCS-3 functional requirement specification issued by the Ministry of Railways, this paper implements the following three aspects: Firstly, some representative functional scenarios of Radio Block Centre (RBC) are selected to build the models by Colored Petri Net (CPN) and to generate the RBC test cases of XML format. Secondly, the sequence sets of test cases may be optimized based on the improved ant colony algorithm and ideological maze. What is the optimization idea is that not only can be the shortest pathes found but also the redundant phenomenon of test sequence generation can be reduced according to the natural law of ants foraging. Finally, the RBC test platform may automatically generate test cases and test sequences for the simulation. The result shows that the proposed method can achieve optimization of test sequences successfully and reduce the test time greatly.