The mountain park has unique ecological background conditions. In order to promote the integration of ecological civilization and urban construction, it is necessary to build an urban ecosystem of harmonious coexistence between man and nature on the premise of ecological protection and urban construction. The construction of mountain sponge in Qifeng Park of Changsha city is taken as an example to explore the construction ideas of mountain park sponge city. The ecological potential of the existing mountain is excavated fully, the design concept of "light engineering, heavy origin" is put forward, the low-impact development model is practiced, while the mountain to the greatest extent is preserved, the sponge facilities such as green roofs, dry streams, ecological retention grass ditches, permeable pavement, and ecological parking lots are cleverly embellished, and the measures are adapted to local conditions and landscaping, the sponge city is integrated into the landscape design, the natural accumulation, natural infiltration, and natural purification of rainwater are realized, the quality and landscape value of the park are improved, and the ecosystem and the surrounding areas of the park are developed, and also the public space of residents is enriched, which can provide reference for the construction of sponge city in mountain parks.