Method for estimating fatigue life of pipeline of nuclear power plant

The invention discloses a method for estimating the fatigue life of a pipeline of a nuclear power plant. The method comprises the following steps: S1, measuring the temperature of the outer wall of the pipeline; S2, calculating information on a temperature field of the inner wall of the pipeline; S3, counting the cycle index of an effective load, determining alternating stress, and amending an S-N curve; S4, calculating a fatigue coefficient and amending the fatigue coefficient; and S5, estimating the fatigue life. The method has the beneficial effects of helping a designer master relevant data of the nuclear power plant under a thermal fatigue environment, optimizing an operating standard and an inspection outline according to the estimated fatigue life, developing the design safety margin of the pipeline of the nuclear power plant and providing data support for the regular audit or lifetime extension of the power plant.