[Objective] Hybrid tower structures have emerged as crucial supporting structures for wind turbine generators in low-wind-speed regions. However

the hybrid towers have a complicated construction process

leading to frequent occurrences of defects such as tower step misalignment and structural adhesive deficiency. These defects pose a significant threat to the structural integrity of the tower

thereby impacting the overall reliability and economic efficiency of wind power projects. There is an urgent need for safe construction and efficient operation and maintenance guidance. [Method] Taking the damage of a 4.2 MW concrete-steel hybrid tower as a case

ABAQUS was used to establish finite element models of the tower structure under various defect scenarios

including joint misalignment

insufficient adhesive at joint interfaces

and excessive pad height

to investigate the influence mechanism on structural performance and derive engineering recommendations. [Results] Excessive pad height

insufficient adhesive application

inadequate concrete strength

joint misalignment

and insufficient pretensioning of steel strands collectively contribute to the degradation of the tower structure's safety. Based on the aforementioned research findings

this paper proposes targeted engineering optimization recommendations.