In order to explore the energy regulation of cut tree peony flower and its relationship with the vase quality, the secondary stage ‘Luoyanghong’ cut tree peony flowers were applied as the experimental materials to investigate the relationship between the cut flower vase quality and the expression of SnRK1, a sensitive gene for energy charge and energy metabolism, under the high energy charge level (natural growth in the field, FNG) and low energy charge level (postharvest of natural growth and stored at 5-6 ℃ for 15 days, PCS). The results demonstrated that: (1) PCS accelerated the opening and senescence processes of cut tree peony flowers in the vase remarkably, and therefore, reduced the vase life and the maximum flower diameter significantly, comparing to that of FNG. In addition, PCS advanced the peak of respiratory climacteric and increased respiratory rate while accelerated sucrose degradation, which led to quick reduction of the activities of petal succinate dehydrogenase (SDH) and mitochondrial complex IV (CCO), rapid declines in ATP and EC levels, advanced PsSnRK1 gene upregulation and increased expression level. (2) The decrease in energy charge level can induce the upregulation of PsSnRK1 gene expression due to its quick respond to energy deficiency in tree peony petals. This study confirmed that the decrease in the energy charge level of petals after refrigeration was one of the important factors that led to the rapid senescence of the cut tree peony flower in vase process. The energy status of petals plays an important role in vase quality regulation of cut tree peony flower, which provides a new strategy to improve the vase quality of cut tree peony flower by regulating the cut flowers energy level.