This article discusses Professor Xiong Lei's experience in treating paediatric febrile syncope based on the theory of "Yang fire and Yin fire" in Chinese medicine, in terms of the etiology and pathogenesis of the disease and the treatment methods and prescriptions. Professor Xiong Lei believes that the basic pathogenesis of paediatric febrile syncope is the imbalance of Yin and Yang, with fire and heat stagnating in the lining. There is a distinction between Yin and Yang in fire, so Yin and Yang is used as a platform for identification and treatment of paediatric febrile syncope from the perspective of "Yang fire and Yin fire". A test case is also attached for verification.