To solve the problem of hybrid beamforming in millimeter wave Multiple-Input Multiple-Output（MIMO）system

a hybrid beamforming algorithm based on iterative updating is proposed.The algorithm improves the system performance by improving the correlation between the analog beamforming matrix and the error matrix.Firstly

the proposed algorithm updates the error matrix iteratively.Then

the singular value decomposition of the error matrix is used to obtain the singular value matrix and then an analog beamforming vector is obtained.Finally

the analog beamforming matrix is updated according to the analog beamforming vector.Compared with the traditional Orthogonal Matching Pursuit（OMP）hybrid beamforming algorithm

the performance of the proposed algorithm is better than OMP algorithm and close to that of fully digital beamforming algorithm

especially when the number of data streams and Radio Frequency（RF）link is similar and small.