For the channel interference of MIMO system in visible light communication, an adaptive spatial modulation technique is used, in which only one LED is in the working state at any time. The receiver uses the maximum likelihood algorithm to restore the original signal. At the same time, the adaptive Fischer algorithm is added to optimize the bit error rate performance. The transmitter can allocate different bits to each subcarrier according to the channel state information to reduce the bit error rate. The experimental results show that the spatial modulation technique combined with Fischer algorithm can effectively reduce the bit error rate performance and improve the communication performance of the visible light communication system under the condition of constant transmissionrate and transmission power.