Dual-network redundancy transmission method and device based on link selection

The invention discloses a dual-network redundancy transmission method and device based on link selection. The method comprises the steps that a data sending node copies message data and sends the message data to two independent and parallel transmission networks through two network cards respectively; and when the data receiving node receives the message data sent by the data sending node from the corresponding transmission network through any one of the two network cards, checking a built-in node link state table, judging whether a record of the data sending node exists or not, if so, judging whether to upload the message data or not according to the record of the data sending node, and if not, sending the message data to the data sending node. The record of the data sending node is updated in the node link state table according to the message data; if not, adding a record of the data sending node into the node link state table, and uploading the message data according to the record of the data sending node;