Method for preventing parameter resetting in IPSec (IP Security) channel updating

The invention provides a method for preventing parameter resetting in IPSec (IP Security) channel updating, wherein the method transmits messages by a master device or a standby device. The method comprises the following steps that: A, a serial number threshold is set; B, the master device transmits the messages, wherein the message contains the serial number, and when the amount of the messages transmitted by the master device reaches the threshold, the master device transmits a synchronization signal to the standby device, wherein the synchronization signal contains the serial number of the current message; C, when the master device and the standby device are switched, the serial number of the current message is determined; and D, starting from the determined serial number of the current message, the standby device transmits the messages. According to the method provided by the invention, when the master device and the standby device are switched, the standby device is used for transmitting or receiving messages, and the serial numbers of the transmitted or received messages are synchronous with that in the master device.