Disclosed are a cross-domain protection interacting method and system. The method includes: an interconnecting node on a cross-domain working path between a first domain and a second domain sends second identification information of the second domain to a first node in the first domain, wherein the first domain and the second domain are neighboring domains; when a link failure occurs in the first domain, an interconnecting backup node between the first domain and the second domain receives first failure state information sent by the first node, wherein the first failure state information carrying the second identification information; and the interconnecting backup node activates a second protection path in the second domain according to the second identification information, and uses a first protection path in the first domain and the second protection path to transmit a cross-domain service. The present invention can ensure protection independence in each domain and achieve an effect of interaction of cross-domain protection.