Chen, Q.X. Chen, J.F. Rong, J. Xing, S. Zong, Y. JACoW Publishing Geneva, Switzerland 2673-5504 978-3-95450-234-9 10.18429/JACoW-SRF2023-WEPWB043 English 655-657 cavity vacuum niobium MMI superconducting-cavity Contribution to a conference proceedings 2023 2023-09 https://doi.org/10.18429/JACoW-SRF2023-WEPWB043 https://jacow.org/srf2023/papers/wepwb043.pdf This paper describes the design of a coating system for the preparation of a superconducting radio-frequency cavity with Nb₃Sn thin films. The device consists of a coating chamber made of pure niobium, a vacuum furnace for heating the coating chamber, a superconducting cavity bracket and two crucible heaters. The chamber is vacuum isolated from the furnace body to protect the superconducting cavity from contamination during the coating process. The device has been built and commissioned, which could be used for Nb₃Sn coating of a 1.3 GHz single-cell superconducting cavity in future.