With the development of large-scale storage tanks,structural safety issues such as foundation settlement and structural deformation that affect the operation of large storage tanks have increasingly become the focus of equipment management and inspection personnel.Research on foundation settlement detection and structural integrity evaluation of large storage tanks is of practical significance for ensuring the safe operation.This article analyzes the types and typical damage forms of tank foundation settlement,and proposes requirements for tank foundation settlement detection based on the characteristics of different tank service stages such as design,construction,and regular inspection.It clarifies the detection and evaluation methods for different types of settlement,and focuses on the research of graded evaluation methods for uneven settlement around the tank.A 4-level evaluation method for basic uneven settlement,including settlement difference evaluation,deviation from the plane settlement amplitude evaluation,local non-uniform plane settlement evaluation,and stress analysis evaluation,is proposed to effectively support equipment management and inspection personnel in conducting structural suitability evaluation under tank foundation settlement conditions.