In a network protection method, a network node, and a communications system provided in embodiments of the present disclosure, when signal degrade or signal fail occurs in a service transmission path, a communication status of a source node of a current protection segment is obtained, and whether to perform protection switching is determined according to the communication status of the source node and a communication status of a local communication path. This can avoid erroneous switching to some extent, thereby improving protection switching accuracy of a communications network.