Abstract: Ecosystem service value (ESV) is the bottom line of regional ecological security, and scientific assessment of ESV changes caused by land use change is of far-reaching significance for building regional ecological security pattern and promoting sustainable development. Based on the land use data of three periods from 2000 to 2020, with the help of ESV equivalent factor, hotspot analysis and ecological contribution rate, this paper explored the land use change and its impact on ecosystem service value in Chengdu. The results showed that: (1) From 2000 to 2020, cultivated land and forest land were the main parts of Chengdu City, and the area change showed that cultivated land and grassland were reduced and other land types were expanded. Land conversion was mainly from cultivated land to forest land and construction land. (2) The overall trend of ESV in Chengdu was "increasing first and then decreasing", with a net increase of 203 million yuan in 20 years. According to the size of ESV, the trend was forest land > cultivated land > water area > grassland > unused land, and the increase of ESV in forest land and water area was the main reason for the increase of ESV in Chengdu, and the sum of the two ecological contribution rate was 53.66%. (3) The single ESV was dominated by regulation services, in which hydrological regulation and climate regulation were the core ecological functions of Chengdu, accounting for 57.52% of the total ESV. (4) The spatial difference of ESV in Chengdu was significant, and the distribution pattern of hot and cold spots was "hot in the west and cold in the east, but not significant in the east". The hot spots were concentrated near Longmen Mountain and the water area in the west, while the cold spots were concentrated in the middle of the central urban areas and constantly shrinked towards the central urban areas. These results indicated that forest land and water ecosystems had greater impact on the overall ESV. Therefore, it is the focus of environmental protection and ecological construction in Chengdu in the future to implement reasonable and effective protection strategies and promote the development of land use structure towards the direction of ESV appreciation and preservation.