Urban parks have significant cooling effects, which can both mitigate the urban heat is-land effect and are crucial to the sustainable development of the human habitat. Although studies have been conducted to explore the influence of urban park morphology on the cooling effect of parks, they are not sufficiently in depth. Therefore, this paper took 117 urban parks in the central city of Chengdu as the research objects based on the perspective of the quantitative classification of urban park morphology. Then, remote sensing interpretation, spatial statistics, and regression analysis were used, and the four indicators of cooling intensity, cooling distance, cooling area, and cooling efficiency of urban parks were integrated to explore the cooling effect of the different morphological types of urban parks. The results show that (1) urban parks in Chengdu could be divided into five categories, among which the cooling effect of round parks was the best, and the cooling efficiency was 0.7. (2) In terms of park cooling area, urban parks’ area and perimeter thresholds were 30 ha and 4000 m, respectively. (3) When the area and perimeter of urban parks reached 70 ha and 3000 m, respectively, the increase in the cooling distance slowed down. (4) The cooling efficiency of the park was best when the shape index (indicating the complexity of the park boundaries) of the urban park was 2.8. The results of the study provide theoretical support for the intensive use of urban park green space and help the construction and promotion of a beautiful and livable park city in Chengdu.