The remediation effects on cadmium, lead, chromium, arsenic and manganese pollution in cultivated land under five different planting densities (165 000, 146 300, 127 500, 108 800, 90 000 plants/hm2) were studied. The results showed that planting density in the 127 500，108 800 and 90 000 plants /hm2, comprehensive growth index were better than that of other plant density treatments; The planting densities of 16 5000 plants/hm2 were higher than those of other treatments; The enrichment coefficients of Cd and Cr in root were more than 6.00, the enrichment coefficients of manganese, arsenic and lead were less than 1, the enrichment coefficient of Pb is only about 0.1. At 165 000, 146 300 and 108 800 plants/hm2, the total uptake of heavy metals was larger. Comprehensive consideration, the best density was 165 000 plants /hm2 to obtain high biological yield and high heavy metal uptake.