JP+1] The complexity introduced by interactions among heterogeneous types of on-board buses requires comprehensive health monitoring on aircraft’s status. In this paper, we introduce a multi-bus monitor system with huge storage capacity with details about the features, major functions and hardware/software design. The system supports to monitor and record 1553B bus, CAN bus and HB6096 bus at the same time. Real-time multitask OS and FPGA has been used in the system to achieve high monitoring/storage performance and reliability.