A brief introduction to current GNSS anti-jamming research situation at home and abroad is given. In combination with the application of BLMS (Block Least Mean Square) in GNSS anti-jamming, the BLMS Algorithm's block diagram and its signal flow chart are given to show how to realize it in hardware, and some problems are analyzed in its realizing process. An in-lab anti-jamming researching method is introduced, that is, using signal generators to simulate the jamming and the satellite navigation signal, and using power divider and synthesizer to simulate the array. Finally, monochromatic jamming and swept jamming are used to test the Algorithm's anti-jamming capability, and its validity is checked by a matlab C/A code correlating program. According to the experimental data, the jamming can be mitigated at large scale when it is suppressive. This offers a valuable reference for GNSS anti-jamming research.