The bottom ash of biomass power plant in South China was used to produce heavy metal deactivator BFA by physical and chemical modification, BFA was used to remediate the cadmium contaminated soil in South China. The reason why we selected the bottom ash was the content of heavy metals such as Cd in bottom ash were significantly lower than that in fly ash. The adsorption capacity of BFA to Cd in water was over 16mg/g. The results of indoor pot experiment showed that, with the amendment of 1% w/w BFA to soil, Cd in rice decreased over 80% in the first season, from 2.8times over the national standard value to lower than the standard; in the second season, Cd in wheat decreased by 70%, from 0.9times over the standard value to lower than the standard. The in situ experiment conducted in the heavily polluted cropland in South China showed that, with the amendment of 1% w/w BFA to soil, Cd in rice and wheat produced decreased by 70%~90%, in the second year (2017), the Cd reduction rate in rice increased by 10%~20% compared with the first year (2016), from 20times over the standard value to lower than the standard. By the way, the Ni in rice and wheat produced decreased over 60%, while the content of beneficial elements, such as Cu and Zn, were not affected signally. the BFA also promoted crop growth, the yield of rice increased by 40%~60% in the first season and still have benificial effects in the second season. The heavy metal content of the bottom ash of biomass power plant in south China is low. The BFA produced by the bottom ash provides an excellent way to dispose of the bottom ash and for the remediation of cropland contaminated with heavy metals in South China.