By compilation of data from field sampling, pot experiment and literature, we evaluated the suitability of the existing national standards (GB 15618-2018 and GB/T 36783-2018) for the classification of soil environmental quality in potato producing areas of Guizhou. The results showed that both soil Cd standards were overly stringent as, for example, these for potatoes grown in mining areas were more likely to exceed food standard. Here, we summarized the inadequacy of the existing sampling methods for soil-crop synchronized monitoring and proposed a sampling theory-based Decision Unit-Multi Increment Sampling method (DUMIS) for soil-crop synchronized monitoring and remediation verification. We proposed that the criteria for safe soil utilization should be derived on a site-specific basis using bioavailable fractions. In order to facilitate the evaluation of soil environmental quality and safety for the agricultural production regions of China, we suggested that further research is needed regarding the use of DUMIS in soil-crop synchronized monitoring and bioavailable fractions based criteria for safe utilization of mild to moderately contaminated soils.