[Objective] The ecological security status of the Gansu section of the main stream of the Weihe River was analyzed in order to provide a theoretical basis for ecological civilization construction of the river basin.[Methods] The DPSIR model was used to construct an ecological security evaluation index system for the Gansu section of the Weihe River. A combined weighting method was used to determine the index weight. An obstacle model was used to diagnose obstacle factors.[Results] ① The ecological safety index of the Gansu section of the main stream of the Weihe River initially decreased and then increased. The level of ecological safety changed from class Ⅳ (more dangerous) to Ⅴ (dangerous) to Ⅳ (more dangerous), and then to Ⅲ (forewarning); ② The project-level index exhibited a small degree of change. Fluctuations in the driving force, pressure, and impact index decreased. Fluctuations in the status and response index increased. The overall ecological security situation improved; ③ Population growth rate, economic growth rate, vegetation coverage rate, urban sewage treatment rate, and agricultural water use efficiency were the main obstacles affecting the ecological security of the Gansu section of the Weihe River.[Conclusion] In the future, greater attention should be focused on the integral unity of economy, politics, culture, and ecological environment, so as to further promote the harmonious development of the economy and ecology.