Abstract: Characters and disadvantages of reference electrode used in molten salt were introduced.The boron nitride membrane Ag/AgCl reference electrode which can be used for high temperature molten fluoride salt was prepared and its performances were studied.The best amount-of-substance fraction of AgCl was 2%，and ensured that the AgCl was uniformly mixed in LiCl-KCl molten salt.In the preparation of the reference electrode，the interfaces should be strictly sealed，in order to reduce the evaporation of salt and weaken the corrosion of oxygen and water on the wire.The performance of the reference electrode was evaluated，it was found that the activation temperature effected on activation time.Temperature had little effect on potential.Polarization reversibility of the reference electrode was good.Stability of the reference electrode was good，but the performances can be influenced by AgCl concentration，temperature，and light.Reproducibility of the electrode was excellent for longer time use.Finally， it was found the reference electrode can be continuously used over a long period of time （at least  28 d） for molten salt electrochemistry experiment.

Key words: molten salt, reference electrode, boron nitride membrane, Ag/AgCl