A spatial multiplexing Multiple Input Multiple Output(MIMO) receiving scheme based on beamforming is proposed. Combining MIMO and Beam Forming(BF)，the proposed scheme takes the advantages of both multi-stream receiving and anti-jamming. Aiming at flat fading channel，a BF-MIMO spatial correlation channel model is set up firstly. Then Bit Error Rate(BER) expression for the system receiving is derived. Finally，the relation between Angle Spread(AS) and system anti-jamming performance is investigated. Theoretical analysis and simulation results show that the proposed scheme could provide better anti-jamming and BER performance than traditional MIMO techniques under small AS environment.