Abstract: The hardware of a kind of regional isolation system has been designed based on the Arm Chip platforms.Using which,the illegal packets are prevented to pass through,by examine the packets flow to these critical equipments with the communication control method and "white list" technology.Several typical network attacks method were used to test the security of the CTCS-3(Chinese Train Control System),which include the scanning attacks,the ARP attacks,the Trojan attacks and the buffer overflow attacks.Resultsshow that security of these devices in this industrial network is reinforced without influence real-time performance of the network.The illegal incursions,the attacks within the network and the spread of the virus are efficiently prevented using this region isolation system.