The selection of appropriate codes for an optical code division multiple access (OCDMA) network, which determines the maximum number of users and bit error rate (BER) supported by the system, is crucial. This study proposed a variable weight zero cross-correlation Latin square (VW-ZLS) code for spectral amplitude coding (SAC)-OCDMA systems, which offers high autocorrelation and zero cross-correlation, while providing differentiated quality of service (QoS) features. Using direct detection (DD) technology, the data rate of the proposed VW-ZLS code reached 4.8 Gbit/s under the condition that BER does not exceed 10-9. This was 0.5 Gbit/s higher than that of zero cross-correlation magic square variable weight optical orthogonal code (ZMS-VWOOC) with the same cross-correlation characteristics. Further, simulation results showed that in SAC-OCDMA system, the VW-ZLS code was better than ZMS-VWOOC and exhibited excellent performance.