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Soil nutrient availability is an important factor influencing heavy metal enrichment plant. The characteristics of soil nutrient slowrelease and the tendency of cadmium accumulation of mustard were studied. A complete combination design of fertilization rate (0, 20%, 40%, 70% and 100% of the benchmark fertilizer application amount respectively, and the benchmark fertilizer application amount was N350kg/m2, P2O5 180kg/hm2 and K2O 180kg/hm2) and carbon application ratio (carbon fertilizer quality ratio of 0, 3% and 9%) were set up in the experiment. The results showed that the soil nutrient slowrelease characteristics and cadmium enrichment trend were well fitted based on the Logistic curve model, and the measured root mean square error ratio was 3.29%~8.37%, and R2 was no less than 0.9570. The fertilizer proportion of soil nutrient with high efficient and slowrelease under combined application of carbon fertilizer was 0.99%~55.18%, the maximum sustainedrelease efficiency of nitrogen and phosphorus was increased by 49.17%~90.00%, 13.25%~37.35%, respectively, and the soil nutrient content was increased by 17.38%~40.93%, compared with that without carbon application. The biomass of mustard with cadmium concentration was increased by 119.65%~263.36% through efficient slowrelease of soil nutrients, and the maximum efficiency value of the biomass in the aboveground part was increased by 166.67%~300.00% compared with the biomass in the root part. The content of cadmium and enrichment coefficient of mustard greens was increased by 97.79%~201.96% in the highly efficient slowrelease interval of soil nutrients. Therefore, in order to meet the requirement of both high efficiency and high concentration of mustard cadmium and fertilizer conservation, the combined application strategy of carbon fertilizer was optimized as follows: the proportion of nitrogen, phosphorus and potash fertilizer under 9% carbon was 60.58%, 61.32% and 21.48%.