Abstract: Conventional electromagnetic environment monitoring methods cannot realize real-time online monitoring of the operating environment of various wireless communication systems in urban rail transit lines. By analyzing the shortcomings of conventional monitoring methods and adopting radio fingerprint identification algorithm, a real-time, online electromagnetic environment monitoring system and test scheme is proposed. Taking LTE-M system and TETRA technology as examples, the composition, architecture, workflow and simulation core interference identification algorithm of electromagnetic environment online monitoring system are expounded. The research results can provide important technical support for intelligent operation and maintenance of urban rail transit wireless communication system.