The invention relates to the field of electrical power system asset management, in particular to an interconnection system reliability assessment method considering a whole life cycle of equipment. The method comprises the steps that (S1) mathematic models are established, wherein a fault rate in each operating period can be modeled considering fault mode characteristics, repair and other factors of the equipment in different operating periods; and (S2) system simulation is performed, wherein during sequential Monte Carlo simulation of system reliability, when the characteristics of the fault rates in the whole life cycle of the equipment are considered, all the operating periods of the equipment need to be determined according to a difference value between a starting moment of a to-be-assessed time period and an equipment commissioning moment, and therefore a fault rate model in the whole life cycle is decided. Through the method, influences of changes of the fault rates in the whole life cycle of the equipment on system reliability assessment can be judged quantitatively.