Due to the imaginary interference, the filter bank multi-carrier with offset quadrature amplitude modulation (FBMC/OQAM) performs poor in context of multiple-input multiple-output (MIMO) communication scenarios. In this article, we propose an imaginary interference-free method for FBMC/OQAM, which is appropriate for both of the subcarrier-based singular valued decomposition (SVD) precoding as well as subband-based precoding with codebook schemes. Specifically, the critical design utilizes a repeated block with the reverse arrangement of symbols. Moreover, we investigate the leakage of imaginary interference of the precoding MIMO-FBMC/OQAM system under frequency selective channel. It is found that these developed precoding solutions may particularly inhibit the inter-carrier interference (ICI) via the meticulous designed symbols block. Theoretical analysis and simulation results over different frequency selective channels validate that the proposed precoding schemes are capable of providing considerable performance gains over the conventional schemes in terms of bit error rate (BER).