[Objective] Through a series of laboratory and field experiments, a computational model of quantum dot spectral suspended sediment monitoring equipment was optimized, and the sources of error were analyzed to lay the foundation for further improvement and application of the equipment. [Methods] An in situ suspended sediment concentration monitoring system using quantum dots was constructed in a laboratory. Reproducibility tests were performed on samples with different sediment concentrations. Laboratory data were divided into training and testing sets, and accuracy analysis was performed to select the best computational model. For the field experiment, the equipment was installed at the Luoyu Gou site at the Tianshui Soil and Water Conservation Monitoring Station. The sediment concentration, measured using the manual replacement method, served as the true value. A comparative analysis was conducted for eight runoff and sediment transport events that occurred between August and September 2023. [Results] The relative errors between the designed and manually measured sediment concentrations ranged from -12% to -28%. The relative standard deviations of the repeatability tests for manually measured sediment concentrations ranged from 0.1% to 5.0%. The fitted index regression model (model 1) and quadratic polynomial regression model (model 2) had determination coefficients of 0.966 and 0.996, respectively, for the training set. For the testing set, model 2 outperformed model 1 in three of the four accuracy evaluation metrics with a determination coefficient of 0.991. The determination coefficient for the field comparison data was 0.939 with an average absolute error of 9.1 g/L. [Conclusion] The quantum dot spectral suspended sediment monitoring equipment demonstrated good stability and reliability. Future improvements in application effectiveness can be achieved by optimizing the installation method, expanding the hardware range, and optimizing the computational model.