This paper presents an operational resilience analysis framework of water distribution networks (WDNs) during the lifecycle period. Four models are established based on the maintenance data provided by a water sector and relative studies, including accident occurrence mode (considering case iron pipes, ductile iron pipes, and steel pipes), accident simulation model (considering leakages and bursts), pipe deterioration model, and repair model (considering plugging and replacement). Based on the four models, the operational resilience index is quantified by Monte-Carlo simulation considering the randomness of accident occurrence time, accident type, and repair time. In order to illustrate the above framework, the fifty-year operational resilience of a real WDN is simulated. Results show that the lifecycle performance curve of the WDN can be divided into three stages: full function (1-10 years), slight decrease (11-30 years), and rapid decrease (31-50 years). In addition, three improved cases are introduced and analysed to provide guidance for local decision makers.