为更好地检测出碳纤维增强聚合物基复合材料(CFRP)中的分层缺陷，特别是近表面缺陷，采用直探头、延迟块探头、水浸点聚焦探头和双晶探头对CFRP层压板进行A扫描、B扫描和C扫描成像检测对比试验。试验结果表明，4种检测技术均能有效检测出2.5 mm厚对比试块中的分层缺陷，且可有效识别出近表面0.4 mm深和远表面23铺层之间的缺陷；采用直探头、延迟块探头和水浸聚焦探头在检测时会形成界面波，对近表面缺陷成像造成干扰，而双晶探头盲区小，定量准确，无界面波干扰, 对CFRP层压板近表面缺陷检出率高，检测更可靠。

In order to better detect the delamination defects in carbon fiber reinforced polymer matrix composites (CFRP), especially near-surface defects, straight probes, delay block probes, water immersion point focus probes and dual crystal probes are used to perform the CFRP laminate A-scan, B-scan and C-scan imaging detection contrast test. The test results show that the four detection techniques can effectively detect the delamination defects in the 2.5 mm thick contrast test block, and can effectively identify the defects between the 0.4 mm depth near the surface and the 2~3 plies on the far surface; straight probes, delay block probes and water immersion focus probes will form interface waves during detection, which will interfere with the imaging of near-surface defects, while dual-crystal probes have small blind areas, accurate quantification, and no interference from interfacial waves, which can detect near-surface defects of CFRP laminates with high rate and more reliable detection.