The performance of min-sum (MS) decoding algorithm depends on each bit corresponding to the accuracy of log-likelihood ratio (LLR) for multi-level cell (MLC). However, uniform sensing strategy needs to increase the sensing precision in order to obtain high accuracy of LLR, which increases the reading latency of MLC. In this study, an MS decoding algorithm is proposed for MLC flash memory, which uses non-uniform sensing strategy for the threshold voltage of MLC. In the same sensing precision, compared to the uniform sensing strategy, the non-uniform sensing strategy can improve the accuracy of LLR and lower the raw bit error rate. The simulation results show that the proposed method can not only guarantee the reliability of the MLC flash memory, but also keep the fast reading speed for MLC flash memory, thus achieving a better tradeoff between complexity and decoding performance.