[Objective] The cooling effect of city parks on the urban thermal environment in Yinchuan City, Ningxia Hui Autonomous Region was studied in order to provide guidance for policy-making to improve cooling of the urban thermal environment.[Methods] Land surface temperature (LST) was retrieved from Landsat 8 remote sensing data, and 17 city parks in Yinchuan City were selected to determine the influence of spatial characteristics of the parks' patch characteristics and landscape spatial structure on the internal thermal environment of the city. The cooling effect distance of city parks to the surrounding thermal environment was analyzed, and its affecting extent was quantified. Further research on the thermal environment effect of a typical urban park water area landscape was carried out using landscape pattern and the buffer analysis method.[Results] ① The landscape patch characteristics were significantly different, and the impact on the internal temperature of the park was significant. The internal temperature was significantly negatively correlated with area and perimeter, but significantly positively correlated with perimeter area ratio. ② The internal temperature of the park was closely related to landscape composition, patch morphology, and landscape spatial distribution. The cooling effect was negatively correlated with the area of green space, waterbody, landscape shape index, green landscape shape index, impervious surface shape index, and water aggregation index. ③ The cooling effect of the 17 park landscapes on the surrounding thermal environment was significant, with the maximum cooling distance mainly distributed between 200 m and 300 m. The cooling effect was most obvious within 100 m. ④ Water patches could effectively reduce LST around the water area, and had a better cooling effect on the urban heat island effect than linear water.[Conclusion] During the planning and design of city parks, designers should comprehensively weigh the impact of park patches and landscape spatial structure characteristics on their cooling effects, focus on the area of park green spaces and water bodies, and try to appropriately increase the complexity of boundary shapes of parks and water patches in order to better improve the cooling effect of the urban thermal environment.