Abstract:Based on the PSR model, the evaluation system of urban ecological security is established, and an improved cloud matter-element model is proposed. By using the double uncertainty of cloud model and matter-element extension theory, the comprehensive evaluation of urban ecological security in Shandong Province from 2009 to 2019 is carried out, and the ecological security and index contribution of Jinan City are mainly studied. The results show that the ecological security index given by the model can not only describe the ecological security situation, but also compare different cities. Although Jinan has been in a critical state of security, the ecological security index has been rising steadily, which is greatly affected by the pressure and state of the ecosystem. The ecological security status of 16 prefecture level cities in Shandong Province has obvious differences, and the overall trend is on the rise, but the overall level is in the critical security level, Weihai, Qingdao and Jinan are in the forefront, while Dezhou, Zaozhuang and Heze are less secure. Shandong provincial government should pay attention to the imbalance of regional development and formulate relevant policies to narrow the gap between cities.