Abstract: The study on the landscape pattern of urban green space can provide basic data for the overall urban planning and ecological construction, and it is of great significance to optimize the urban spatial structure and improve the ecological function of urban green space. Based on the "3S" technology and Fragstats 4.2 software, 12 landscape indexes were selected from patch level, type level and landscape level to carry out quantitative analysis on the ecological pattern of green space landscape in the main urban area of Nanchong city, and optimization countermeasures were put forward. The results showed that: (1) there were 12,822 green patches in the main urban area of Nanchong city, with a total area of 5,707.53 hm², and the green space coverage rate was 40.39%. The landscape types were abundant, but they were relatively fragmented. (2) Among all types of green space, the area of regional green space was the largest, accounting for 37.43%, followed by park green space, accounting for 30.50%. The patches of regional green space and park green space were relatively complete, while all kinds of affiliated green space and protective green space were relatively fragmented. The patch shape of park green space, protection green space and regional green space was simple, and less affected by human activities. On the contrary, the green space affiliated to roads and residential areas was complicated in shape and greatly influenced by human beings. (3) All kinds of green space were unevenly distributed among different areas. In particular, the park green space was mainly distributed in Shunqing district, accounting for 56.48% of the total park green space, and the park green space in Gaoping district was the least, only 10.87%. Except for the park green space and regional green space, all other green spaces in the three districts showed a large degree of patch dispersion. In the future urban green space construction, much attention should be paid to improve patch types, optimize patch layout, appropriately increase the number of medium and large patches, connect fragmented patches and increase landscape spatial connectivity, in order to provide guarantee for species migration and energy flow. Finally, special attention should be paid to the development and utilization of attached green space and mountain green space, and the service radius between green patches should be increased to make the spatial distribution more reasonable.