随着工业化的快速发展，人民生活水平的不断提高，私家车也步入普通家庭，公路交通的压力也随之而来。交通压力的剧增导致了车祸的不断增加，不但造成了人身伤害与财产的损失也使得家庭陷入巨大的困境。如何让驾驶车辆成为安全的出行方式，就成为人们追求的目标，所以对于车辆安全检测技术的研究就具有更为重要的意义。 本文重点研究车辆安全距离的测量与车辆目标的追踪，安全距离是车辆行驶中保证人身安全的必要条件。目标车辆追踪以及距离测量客观的反映了当前的路况信息，该辅助技术能够有效减少交通意外的发生。 论文深入分析了国内外基于视觉车辆安全检测技术的研究现状和发展。介绍了车辆主动安全系统的结构并对车辆测距以及车辆追踪进行深入的研究，重点在于安全距离的测量以及车辆目标追踪算法的研究。针对车辆测距系统，分析对比了常见的测距方法，并研究了它们各自在实际工程环境应用中的缺陷，最后采用基于SIFT特征点匹配的测距方法，在SIFT特征点匹配过程中构造新的匹配约束函数，实验结果验证该测距方法可以减少匹配时间，同时也可以减少极少数的特征点的跳变而造成的误差。针对目标车辆追踪，分析对比了各种车辆目标追踪方法，提出了将矩不变与基于更新固定模板相结合的目标追踪算法，并采用Matlab软件以及OPENCV进行编程仿真实验，通过实验可知，本文算法可以有效的改善车辆运行过程中尺度、旋转、遮挡等原因造成的追踪丢失现象，进一步验证了车辆安全距离测量以及车辆追踪的可实施性和准确性。

With the rapid development of industrialization, the improvement not in people's living standard,but also into the average family car, so that the pressure increase in private car road traffic surge, also led to increased car accident, car accidents not only cause personal injury and property the loss also makes families into huge trouble. How to make the vehicle a safe way to travel has become a goal of people, so the research on vehicle safety technology has a more vital significance. The measurement of vehicle safety distance and the tracking of the vehicle target is researched intensively in this paper,the safe distance is the essential condition for the vehicle running to ensure the personal safety.The current traffic information is reflected by target vehicle tracking and distance measurement objectively, the occurrence of accidents in traffic accident.can be reduced by the assistant technology effectively. The research status and development of the visual vehicle safety detection technology based on domestic and foreign is analyzed deeply.The structure of the active safety system of vehicles is introduced and the vehicle ranging and vehicle tracking.is studied,The emphasis is on the safety distance measurement and the vehicle target tracking algorithm.Aiming at the vehicle ranging system, the common ranging method is analyzed and compared, and the defects of their application in the practical engineering environment are studied.Finally, The matching method based on the SIFT feature point , a new matching constraint function is constructed in the process of SIFT feature points matching.This method can reduce the matching time and can also reduce the error caused by the jump of the rare feature point is.show through Experimental results.The tracking method of various vehicle targets is analyzed,aiming at the target vehicle tracking, and the target tracking algorithm based on the moment invariants and the updating fixed template is proposed.The simulation experiments were carried out with Matlab and OPENCV,The tracking lost phenomenon can be improved effectively which is caused the by the running process of the vehicle scale, rotation and occlusion,through the experimental results,the implemented and accuracy.of the vehicle safety distance measurement and the vehicle tracking is further verified.