The over exploitation of natural sources leads to a huge burden on water, air, and other environment, among which the response of water environment is the most direct and rapid. With the interdisciplinary development and technology progress, more and more attention has been paid to rivers and their surrounding ecological environment as an integrated river ecological corridor, but there are few researches on river ecological corridor in China. This article summarizes the fundamental theory and extraction methods of river ecological corridor. The river ecological corridor can be defined as the river itself, the riparian vegetation zone along the river and all the related ecological elements, through which river network and ecological flow connect. The extraction methods of river ecological corridor can be classified to direct or indirect categories. The river ecological corridor can be directly extracted according to regional planning or field observation, or indirectly by the framework of "source identification-resistance surface construction-corridor extraction". The patches with high ecosystem service value are often identified as the source area; the resistance surface is often constructed by different environmental variables, such as land use type, elevation, slope, and others, and these environmental variables are given weight according to experience or expert consultation; then the ecological corridor is extracted by different models combining source area and resistance surface. In this paper, these two extraction methods are summarized in detail, and their advantages and disadvantages are discussed as well. The results show that the indirect extraction method has more practical significance, and can more clearly explain the connectivity between patches in a larger watershed. Meanwhile, the indirect extraction method is more time-saving and convenient with the help of RS and GIS technology. With the advantages of indirect extraction method, the extraction idea of river ecological corridor in Baiyangdian-Daqing River Basin is proposed. The area of Baiyangdian-Daqing River Basin is 45000 km², including Xiong'an New Area and Tianjin Binhai Industrial belt. Different industrial clusters drive the development of whole basin. Incorporated with the ideas of region and watershed collaborative management, a river ecological corridor radiating outwards from the core-Baiyangdian Wetland is gradually formed, thereby realizing the goal of water quality improvement and biodiversity stability in the river basin, and comprehensively improving the quality of reginal ecological environment. At the end, future research directions are proposed in the weak links of scientific improvement of river ecological corridor extraction and width optimization of river ecological corridor.