In order to reveal the differences between different peony varieties and facilities, thousands of tissue culture seedlings of 21 Itoh peony varieties imported from abroad were used as test materials, and the peony domestication cultivation method used in the past was used as a control. The technical measures and mechanisms for the outdoor domestication of seedlings and the survival of field transplantation were studied. The results indicate that the main factors and measures for effectively protecting the outdoor transplanting of tissue culture seedlings include cultivating sound and strong seedlings, transplanting in proper period of spring, and providing good ventilating places and facilities, removing leaves, keeping buds and releasing dormancy before transplantation, planting depth should be exposed to the root neck, changing the pots according to the size of seedlings, the substrate should be loose and permeable, seriously disinfected and sterilized, scientific management, and prevention and control of diseases and insect pests. In addition, the survival mechanism was also analyzed, and the reasons and countermeasures for the successful application of peony tissue culture in China were found. Finally, the differences in survival rates between different varieties and facilities were summarized.