Urban parks can help alleviate the urban heat island effect and reduce urban cooling energy consumption. In this paper, we used Landsat8 remote sensing data and land use data, combined with ENVI, ArcGIS, Fragstats, SPSS, and other software tools to analyze the impact factors of the cool island effect in a selection of 44 major parks from the central city of Zhengzhou City. Studies on the cool island intensity were carried out from three aspects: landscape characteristics, landscape composition, and landscape configuration. Results showed that, under limited site conditions, park areas of approximately 20 hm² can produce higher cool island intensity than smaller ones; the simpler the boundary of the park, the stronger the cool island effect; and the more complex the boundary between plants and impervious surface patches, the stronger the cool island effect of the park. In the same area, the cooling effect of parks with a water body is approximately 1 ℃ different from that of parks without any water body. The remarkable intensity of cold island was observed in parks where the water bodies represented 14% of the park's surface. In the park landscape configuration, the combination of plants and water in the park can produce a better cooling effect than the combination of impervious surface and plants or the combination of impervious surface and water. The standard deviation ellipse tool was used for further analyzing the directionality of cool island strength in parks. The conclusion was that the direction of a cool island from a park is mainly related to the direction of the long axis of water bodies present in the park and the distribution of high-rise buildings outside the park.