In order to study the effects of the combined application of controlled-release urea (CRU) and controlled-release potassium chloride (CRK) on soil fertility and peony growth,and provide a theoretical basis for the controlled-release fertilizer (CRF) to replace traditional chemical fertilizers in peony large-scale cultivation,field experiments were arranged,normal urea with potassium chloride base-fertilizer and top-dressing which used by farmers was set as a control,fertilizers with different dosage of CRU (135,270,405 kg/hm²) and CRK (90,180,270 kg/hm²) were chosen,the effects of interactive one-time fertilization on soil nutrient supply capacity and peony growth of "Huang Cuiyu" variety were studied. The results showed that the cumulative nitrogen release rate of CRU reached 80% at 84 days in 25℃ still water extraction,and the release rate of CRK reached 80% at 112 days,which had superior stable and sustainable nutrient supply capacity. With the same amount of fertilization,compared with farmers' customary fertilization (Control),the content of nitrate nitrogen,ammonium nitrogen,and available potassium in soil 0—20 cm soil layer was significantly increased by 68.0%~157.8%,46.6%,and 16.1%~122.6%; the same amount of CRF treatment increased the peony plant height by 8.6%,the stem diameters were increased by 25.3%,the flowers per plant number increased by 25.1%. The CRU and CRK treatments had a significant interaction influence for the soil nitrate nitrogen content,peony leaves net photosynthetic rate,intercellular carbon dioxide concentration,and transpiration rate. The optimal amounts of CRU and CRK fertilization of this study were 270 and 90 kg/hm²,respectively. One-time application of CRU and CRK saves time and labor compared with customary fertilization,improves soil fertility,and promotes peony growth,which has higher promotion value in peony planting.