In communication reconnaissancemulti-channel Blind Source Separation (BSS) algorithm is commonly used to separate signalsbut sometimes the separation effect is not ideal.Through theoretical analysis and simulation verificationthe separation performance of common multi-channel BSS algorithms such as FastICAInformax and EASI in communication signal reconnaissance is studied.The influence of Signal to Noise Ratio (SNR)Signal Intensity Ratio (SIR) and relative Direction of Arrival (DOA) on multi-channel BSS is analyzedwhich provides a reference for BSS application research and algorithm selection.