Cloud model theory was used to assess lake water quality by comparing water samples to quality standards. A new model called MSPSCM was developed to analyze water quality parameters from Nansi Lake in China. Results showed that total nitrogen and phosphorus were the main sources of pollution. Despite some pollution in certain areas, the lake generally meets water quality standards and can be treated for drinking. The MSPSCM model was found to be more accurate than existing methods for evaluating lake water quality.