The correlation dimension is a kind of characteristic parameter of the chaotic system, the definition, parameter selectionand calculation of the correlation dimension was researched in this paper. Anultrasonic Lamb wave damage detection method for the plate composite material based on the correlation dimension was proposed.By calculating the correlation dimensions of collecting the healthy and lossless signals, and comparing the difference between them, the data difference is used as a damage index for the damage location imaging of the probabilistic imaging algorithm.The finite element analysis is used to simulate the experiment, and the experiment investigation shows that the proposed probabilistic algorithm can accurately locate the delamination defects of composite materials.