Abstract: ObjectivesThe problem of difficult detection of high-temperature steam leakage points in fog environments was studied. Methods Based on the Mie theory, numerical calculation methods were used to investigate the effects of the geometric standard deviation, water fog volume fraction, and light path length on spectral transmittance. An experimental platform was built in a laboratory environment to verify the simulation results. Results The results show that the wavelength band selection for optical detection of high-temperature steam leakage points in fog environments should focus on the long-wave infrared band, with the specific range determined to be 10μm~12μm. Conclusions This lays a theoretical foundation for the wavelength selection of high-temperature steam leakage detection in special scenarios such an industrial production environments, narrow spaces, enclosed spaces, and high-dose radiation spaces.