A highly reliable and deterministic communication network is required to guarantee the protection switch control and data acquisition of International Thermonuclear Experimental Reactor (ITER) pulsed power electrical network (PPEN) substation. This study aims at quantitatively assessing the availability indices and evaluating the end to end (ETE) time delay performance of PPEN communication network. The overall architecture of PPEN communication network is first introduced. Theoretical analysis of PPEN communication network under unrepairable and repairable condition are then examined and sensitivity analysis are carried out to find out the best way to improve the availability. Subsequently, OPNET modeler is used to simulate the message communication in PPEN communication network and time delay test was taken to prove the correctness of simulation model. The results indicate that PPEN communication network's availability indices meet ITER's requirement and the ETE time delay conforms to IEC 61850.