系统介绍了激光-电磁超声检测技术的检测原理和技术特点。针对连铸钢坯中存在的多种类型缺陷，研究了钢坯表面、近表面和内部缺陷的检测方法。建立了激光-电磁超声检测系统，并对含有尺寸为30 mm×0.2 mm×0.2 mm的表面裂纹、 3 mm×30 mm的近表面横通孔以及 3 mm×30 mm的内部横通孔的人工缺陷试样进行了检测。试验结果表明，该方法适用于钢坯缺陷的检测，且该技术在高温、腐蚀和高速运动等苛刻环境下的金属材料检测方面具有明显的优势和应用前景。

The principle and character of laser-EMAT testing technique have been introduced in detail in this work. The method used to test the defects in the steel(including the surface, sub-surface and inner defects) has been investigated. The laser-EMAT testing system was set up, and the experiments were carried out on the steel specimen containing the surface crack(30 mm×0.2 mm×0.2 mm), sub-surface hole ( 3 mm×30 mm) and inner hole ( 3 mm×30 mm). The results showed that the method was suitable for testing steel. There is a clear prospect of laser-EMAT testing technique applied to test metal materials at high temperature, corrosion or high speed conditions.