The invention discloses a method and a system for evaluating the protective performance of a multiplexing section. The system comprises a data acquisition device and an evaluation calculating device which are connected. The method comprises the following steps: acquiring network resource data related to multiplexing section protection (MSP) to be evaluated from a network element management system managing the MSP to be evaluated or each network element equipment forming the MSP, and acquiring the operating state data of each network element equipment from each network element equipment forming the MSP; and calculating each performance index value of the MSP by the acquired network resource data and operating state data by a preconfigured evaluation algorithm. The invention greatly improves the efficiency of network maintenance and routing inspection, reduces the operating maintenance cost of the network, and enables network evaluation and analysis as daily maintenance and inspection of the network to be possible and realizable, thereby providing a concrete basis for healthy and intelligent development of the network and optimization and capacity expansion of the network.