Abstract: It is a difficult technique to reclaim the tailings contained toxic heavy metals in safe and economic method at home and abroad. In order to investigate the safety and economy of containing- toxic heavy metal slag field reclamation and planting crop,the authors study the relationship and the heavy metal content characteristics of the overlying soil, crops and soil covering thickness in the investigated in-situ tail slag. The results showed that the tail slag for soil and crop provides the rich heavy metals source. The heavy metals Pb is far higher than Cd and Hg in the tailing slag, soil and crops site conditions. Compared to the national standard, the heavy metals risk of crops in the mature-later is higher than the ones in the early maturity. The risk of leafy vegetables, fruit vegetable and grain crops are mainly from Hg, Pb and Cd three elements. And root vegetables is relatively safe and economic crops, the economic security thickness of radish, potatoes and vegetables planting is greater than 40cm, 50cm and 70cm, respectively. But the other crops planted at a maximum thickness of 90 cm are also unsafe. After planting crops, the Pb and Cd decreased values in soil have a certain correlation with the soil thickness above slag tail. But Hg element has so much to do with the soil thickness and its volatile. Both crops choice and heavy metal mobility are important influence factors for the heavy metals contents of corps. The results can provide a reference for the research of gold tailings reclamation.