FlexRay bus is a new type automotive bus. Designing the test system which can test the reliability and robustness of the bus is very important because the line control system in automobile needs FlexRay bus with high reliability. The system contains six FlexRay nodes. Each of the nodes is equipped by microprocessor, FlexRay controller and a variety of interface circuit. As a result, they can connect with many sensors in order to achieve data communication. The faults generating devices can generate fault frame for all predefined errors. The reliability of FlexRay bus can be evaluated by testing others behavior of nodes to the fault frame. The experimental results demonstrate that the test system can produce fault frame for all kinds of faults and it has some advantages that others FlexRay analyzers can not obtain so far.