Performance of orbital angular momentum (OAM) multiplexing communication system is inevitably degraded by the misalignment of OAM modes between the transmitter and receiver. Aiming at OAM state multiplexing system, a scheme used to reduce influences on system performance of the OAM misalignment between the transmitter and receiver is proposed by adopting multiple-input multiple-output (MIMO) equalization technology. The proposed scheme corrects or partially corrects the intermodal crosstalk of OAM state caused by misalignment of the transmitter and receiver ends. Numerical simulation results show that the proposed scheme can effectively reduce crosstalk between OAM modes of misaligned communication system, and the system bit error rate performance is improved. In the case of small lateral displacement and angular deflection, the system bit error rate can be increased by one or two orders of magnitude.