The invention discloses a tunnel lining defect non-
destructive testing method, and relates to the technical field of non-
destructive testing. During operation of a
system, an
image acquisition device is used for acquiring continuous image sequences of a tunnel lining,
spatial registration is realized based on
feature point matching between adjacent image sequences, an initial multi-
source image set is obtained, the initial image set is preprocessed, and the initial multi-
source image set is obtained; obtaining an enhanced multi-
source image sequence, carrying out
feature extraction and defect detection, extracting hidden crack edge features by adopting a multi-scale convolutional network, inhibiting dynamic interference in combination with an image-to-image
time sequence difference detection model, generating a segmentation image of a hidden crack
defect region, and carrying out segmentation on the hidden crack
defect region; the method comprises the following steps: identifying hidden cracks, acquiring width and depth indication characteristics and position parameters of the hidden cracks through crack
skeletonization mapping, inputting the width and depth indication characteristics and position parameters into a multi-
task learning model, constructing a defect severity index based on the identified hidden crack parameters, performing
health assessment on the evolution state of the hidden cracks in combination with
time sequence trend prediction, and automatically generating maintenance priorities, risk levels and maintenance suggestions.