For the support of a variety of technologies, the intelligent monitoring under the network environment develops rapidly. It is widely used in manufacturing, smart security, image retrieval, medical image analysis and other fields. Meanwhile, the study of its key technology, computer vision is at the leading edge of the field of high-tech research. Currently, the computer vision technology faces many problems such as vague description of semantic information and inefficient. Based on the study of current technology of intelligent monitoring under the network environment, this article aims to review and analyze the pathway of its development, then discover and summarize the internal relations among the core technologies and try to predict the development trends of the intelligent monitoring under the network environment. Additionally, the detailed description of visual tracking, one of the hotspot studies especially the condition of multi-camera collaborative work is presenting in the article.