Abstract: As honeycomb, structure composites are more and more widely used in aerospace industry, the nondestructive testing also demands higher requirements. But conventional ultrasound inspection has a slow scanning speed and is hard to analyze the result. By comparison, phased-array inspection uses electronic scanning mode that enhances the scanning speed greatly, and with C-scan, it makes the analysis of the results much easier. Three cases using phased ultrasonic testing technique to detect the different types of honeycomb-structure composite pieces were introduced. Testing results showed that phased array ultrasonic technique could effectively detect the defect of lack-glue, and has a good application prospect in this field.