Abstract: One coastal power plant outdoor tank was detected by mean of magnetic flux leakage, phased-array ultrasonic, and robotized ultrasonic C-scan. It is found that the maximum stress intensity at the corrosion pit is far lower than the allowable strength of the material, and the structural safety meets the requirements. According to the evaluation results, the corrective action suggestions for the outdoor tank of the plant are put forward. At the same time, the preventive management strategy optimization suggestions are put forward based on the management status of domestic coastal power plant outdoor tank.