Studying the recreational function of the Qinghai-Tibet Plateau National Park Group can help promote the sustainable development of the Qinghai-Tibet Plateau and provide a reference for the construction of national parks in China. This article traces the theoretical basis of recreational function, clarifies the definition, characteristics and application direction of recreational function. Then, we analyze the natural basis of recreational function of the Qinghai-Tibet Plateau National Park Group and propose the realization path. The main conclusions are showed as follows. (1) The recreational function is the degree of support or guarantee of human recreational activities formed by ecological geographical elements, with three characteristics of attribute dependence, potential, and achievability. (2) Ecological geographical elements are the formation of recreational functions. The natural foundation of the recreational function of the Qinghai-Tibet Plateau national park includes topography, land cover, unique landscape, ecological flora, and climatic conditions. These conditions jointly affect the suitability of recreational development of the Qinghai-Tibet Plateau National Park Group carrying capacity with recreational development. (3) The realization path of the recreational function of the Qinghai-Tibet Plateau National Park Group includes reasonable forms, ecological facilities, impact control, franchising and collaborative sharing.