The invention provides an LEU device processing board and a communication processing apparatus and method thereof. The apparatus comprises a configuration information processing module used for receiving configuration information and verifying the configuration information; an Ethernet data processing module used for receiving data sent by an external device through an Ethernet interface and storing the data in a first cache queue, polling a second cache queue and sending the cache data of the second cache queue to the external device through the Ethernet interface; and a CAN bus data processing module used for receiving message data from a security processor through a CAN bus and storing the message data in the second cache queue, polling the first cache queue and sending the cache data of the first cache queue to the security processor through the CAN bus. The processing of the CAN bus communication protocol and the Ethernet communication protocol is incorporated into a non-securityprocessor, thereby reducing the complexity of the security processor and improving the security and reliability of the processing board.