Abstract: In order to investigate the detection capability of terahertz nondestructive inspection technology for the bonding adhesive quality of the adhesive layer between composite material and metal plates, some artificial defects with different characteristics were made on insulation boards in advance and detected with the German SynViewScan 300 continuous terahertz imaging system. The results show that terahertz wave can penetrate the composite material and retrieve two-dimensional terahertz image of the adhesive layer. Those different defects can be clearly distinguished from the terahertz images. The results demonstrate that terahertz non-destructive analysis provides attractive features for the inspection of adhesive quality and the off sticky situation of the composite material.