本文介绍了利用计算机图象系统对具有复杂轮廓的热轧螺纹钢进行在线检测的技术。提出了用可控频闪光源照明和面阵ＣＣＤ成象方式获取高速运动体的清晰图象，设计了新的图象处理算法，能同时给出热轧螺纹钢的多个参数。实验证明测量具有高的精度，可有效实现螺纹钢的在线检测。 This paper presents a technique of on-line inspection of hot-rolled rebar with complex contours using computer vision systems. A clear image of high-speed moving body is obtained by controlled stroboscopic light source illumination and area array CCD imaging. A new image processing algorithm is designed and several parameters of hot rolled rebar can be given simultaneously. Experiments show that the measurement has high precision, which can effectively realize online detection of rebar.