To address the challenges of flow-induced vibration monitoring and prevention in typical industrial pipelines, a method for predicting fatigue life based on the equivalent power spectral density is proposed. First, a fatigue monitoring model is established, and a pipeline vibration test bench is constructed through simulation. Using experimental results as examples, fatigue life estimates are calculated using both the time-domain rain-flow counting method and frequency-domain methods, and their performances are compared. The results show that the frequency-domain method based on equivalent acceleration power spectral density effectively reduces spectral leakage and provides better prediction of fatigue life for pipelines than traditional frequency-domain approaches. On average, the prediction accuracy improves by 3.53%, and the mean prediction error is the lowest. This study offers an effective approach for predicting the remaining fatigue life of industrial pipelines and offers a novel method for fatigue damage assessment.