[Objective] The effects of the adoption of nitrogen and phosphorus fertilizer on the passivation effectiveness of super absorbent polymer(SAP) on heavy metal Pb and Cd in soil are studied in order to reveal the coordination mechanism of moisture and fertilizer conservation and heavy metal pollution control, and provide reference for SAP application rules.[Methods] We adopted the soil column leaching method, testing the impact of nitrogen and phosphorus fertilizer on SAP's passivation effectiveness on Pb and Cd in the contaminated soil.[Results] When SAP dosage was 1.0 g/kg in lead and cadmium contaminated soil, the effect of nitrogen conservation and phosphorus activation synergism was better. Pb accumulative leaching loss amount was reduced by 5.1% compared with comparison group without SAP, and Cd was 13.6% higher than the contrasting group. In the comparison experiment of adding nitrogen and phosphorus fertilizer in the soil, it showed that the accumulative leaching loss of Pb was increased by 76.7% when soil with SAP treatment was added with nitrogen fertilizer, the cumulative leaching loss of Cd increased by 47.6%, and the cumulative leaching loss of Pb was reduced by 26% when adding with phosphate fertilizer, and the cumulative leaching loss of Cd decreased by 20.5%; Besides, the cumulative leaching loss amount of Pb decreased by 2.3% when adding nitrogen and phosphate fertilizer compound in the soil treated with SAP, and that of Cd increased by 8.3%.[Conclusion] SAP has the effect of conserving nitrogen and activating phosphorus, and has passivation effect on Pb and Cd in soil; nitrogen fertilizer inhibites SAP's passivation effect on Pb and Cd, and phosphate fertilizer promotes the work. Nitrogen and phosphate fertilizer compound on SAP's passivation impacts on Pb was not significant, and it inhibited the SAP's work on Cd.