A network communication security processor, comprising: a data communication interface for transferring a communication data packet between the network communication security processor and an external network; an encryption operation module for performing encryption/decryption operations on the data packet; a secure connection database for storing the security policies and secure connection parameters relevant to the data packet; a secure connection database operating engine for operating and maintaining the secure connection database; and a multi-channel security processing engine for invoking the encryption operation module to perform security processing on the data packet; wherein the data communication interface comprises multiple physical interfaces being adapted to connect to different networks, and the data communication interface is adapted to receive data frames through the physical interfaces, remove communication interface encapsulation of receiving data frames to form data packets and is further adapted to add communication interface encapsulation to data packets to form data frames, and transmit the data frames through the physical interfaces; characterized in that, the network communication security processor also comprises: an incoming and outgoing data packet dual-port cache for caching data packets incoming to and outgoing from the network communication security processor and their status information; an incoming data packet selector for retrieving data packets incoming to the network communication security processor from the incoming and outgoing data packet dual-port cache and receiving data packets from a central processor; and an outgoing data packet selector for collecting data packets from the incoming data packet selector and the multi-channel security processing engine, judging whether destination IP address of the data packet is the IP address of the network communication security processor, and if yes, transferring the data packet to the central processor; if not, caching the data packet together with its status information into the incoming and outgoing data packet dual-port cache. a data communication interface for transferring a communication data packet between the network communication security processor and an external network; an encryption operation module for performing encryption/decryption operations on the data packet; a secure connection database for storing the security policies and secure connection parameters relevant to the data packet; a secure connection database operating engine for operating and maintaining the secure connection database; and a multi-channel security processing engine for invoking the encryption operation module to perform security processing on the data packet; wherein the data communication interface comprises multiple physical interfaces being adapted to connect to different networks, and the data communication interface is adapted to receive data frames through the physical interfaces, remove communication interface encapsulation of receiving data frames to form data packets and is further adapted to add communication interface encapsulation to data packets to form data frames, and transmit the data frames through the physical interfaces; an incoming and outgoing data packet dual-port cache for caching data packets incoming to and outgoing from the network communication security processor and their status information; an incoming data packet selector for retrieving data packets incoming to the network communication security processor from the incoming and outgoing data packet dual-port cache and receiving data packets from a central processor; and an outgoing data packet selector for collecting data packets from the incoming data packet selector and the multi-channel security processing engine, judging whether destination IP address of the data packet is the IP address of the network communication security processor, and if yes, transferring the data packet to the central processor; if not, caching the data packet together with its status information into the incoming and outgoing data packet dual-port cache.