In the area of modern electronic warfare, two or more radiation sources are always placed within a certain range to prevent the attack from anti-radiation missile. These radiation sources are placed closely and their parameters are identical. In the case of multiple radiation sources, traditional direction finding algorithms of wideband signal cannot achieve good direction finding precision. Therefore, the single baseline system is set. New signals are created by the conjugate multiplication of signal spectrums received by two antenna array. According to the spectrum structure relationship of new signals, the time delay estimation of radiation sources can be obtained indirectly. And the precision of the time delay can be improved by wiping off the direct current component. The method has the feature of simple equipment. Simulation results show that the algorithm has good direction finding precision under certain conditions.