In order to further reduce the bit error rate of mlti-user mlti-cell visible light comnnication systems using non-or-thogonal multiple access/orthogonal frequency division multiple access(NOMA/OFDMA) technology, a joint power and subcarrier allocation algorithm is proposed. This algorithm aims to minimize the system's symbol error rate by achieving the joint optimal allocation of carrier and user power across sub-cells. Firstly, the symbol error rate expression of the system is theoretically derived. Then, Matlab software is used to simulate the visible light communication system model, and the optimal allocation results are obtained through genetic algorithms. Finally, the proposed algorithm is compared with existing algorithms. The simulation results show that the symbol error rate performance of the proposed algorith is superior.