Objective The study evaluated the land ecological security in Shannan City of Tibet Autonomous Region, revealed the main factors affecting the land ecological security, with a view to providing reasonable suggestions for the realization of ecological environment protection and sustainable land use in Shannan City, and promoting the sustainable and healthy economic development on the premise of ensuring the land ecological security.

Method An evaluation index system of land ecological security was established based on Pressure-State-Response (PSR) Model to evaluate the state of land ecological security in the city from 2010 to 2020, and the main factors affecting land ecological security were identified by Obstacle Degree Model (ODM).

Result From 2010 to 2016, the land ecological security index of Shannan City was between 0.41 and 0.50, showing a slight fluctuation. It continued to decrease from 2016 to 2018, and decreased to 0.44. From 2018 to 2020, the land ecological security index increased rapidly from 0.44 to 0.69, which was closely related to the economic development and ecological environment protection strategies of Shannan City. Among the pressure, state and response indexes, the impact of pressure index on ecological security had little change, and its proportion in ecological security index increased from 29.19% in 2010 to 31.46% in 2020. The influence of state index decreased significantly from 41.62% in 2010 to 29.39% in 2020. The influence of response index increased significantly, from 29.19% in 2010 to 39.16% in 2020. The main influencing factors of land ecological security in Shannan City from 2010 to 2020 were per capita GDP, per capita rural disposable income, annual expenditure of environmental protection and fixed-asset investment.

Conclusion In order to en sure the land ecological security of Shannan City, it is suggested to increase the annual expenditure of environmental protection and optimize the investment structure of fixed assets in a coordinated way while developing economy rapidly and increasing per capita GDP and rural per capita disposable income in the future.