Automated object detection algorithm is an important research challenge in many applications such as computer vision and urban surveillance systems. Recently, quantum computing and information processing become emerging technologies which attract researchers' increasing attention and some work has been attempted in image detection using quantum computing approach. In this paper, we propose a novel quantum automated object detection algorithm for urban surveillance systems. This novel quantum based method is shown to be capable of detecting an object in images accurately and is able to deal with the measurement errors caused by the quantum measurements in the image retrieving process.