Abstract: Taking Lanzhou city as an example, the land ecological safety evaluation system of Lanzhou city is constructed by using PSR model. Selecting 16 indexes, and the weight of each index is calculated by using entropy method, and the evaluation level of Lanzhou land ecological safety is delimited according to the comprehensive index. The results show that the comprehensive index of land ecological security in Lanzhou city shows a fluctuating upward trend from 2007 to 2016, with a small fluctuation. From 2007 to 2010, the safety level is in the critical safety state. In 2011, the safety level became less safe. 2012—2015 safety level is in critical safety state; Through the self-regulation of the ecosystem and the continuous efforts of the society, the security level became relatively safe in 2016. Therefore, in order to ensure that the social economy of Lanzhou can continue to develop in a stable ecological environment, it is necessary to resolve the contradiction between land ecological pressure and land ecological security in the future development, and effectively improve the land ecological security situation in Lanzhou city.

Key words: land ecological security, PSR model, entropy weight method, Lanzhou city