This study advances the in-situ monitoring of suspended sediment, building upon previous equipment development to design experimental protocols and validate laboratory models. The Luoyugou section of the Tianshui Soil and Water Conservation Monitoring Station served as the field test site. We conducted a comparative analysis between automatically collected field data and manually measured sediment concentrations to evaluate system errors and their sources. The results show that in laboratory simulations with varying sediment concentration gradients, the quantum dot spectral suspended sediment measurement system achieved a correlation coefficient of 0.998 with manual monitoring data. During sporadic rainfall-runoff events in the field, the system maintained a high correlation coefficient of 0.984. The monitoring equipment has shown improved environmental adaptability and reliability of results both in artificial simulation experiment and field experiment, and has relatively good applied basic of automatic monitoring of suspended sediment in soil and water conservation.