Based on pot experiment in different acid red soil, the effect of desulphurizaion byproduct on radish nutrition and the mechanism was studied, and the result showed as follow: (1) rich calcium of desulpurization byproduct has high biological validity for radish if used properly, in granite red earth or granite lateritic red earth, the suitable rate of desulphurization byproduct is 5-10g·kg^-1, however, the proper rate of desulphurization byproduct in arenaceous shale lateritic red earth is 10~20g·kg^-1 or so; (2) in this study, proper use of desulphurization byproduct eliminated the obstacle factor induced by calcium absence that affect radish nutrition absorption, so promoted nutrition uptake, boosted radish growth and enhanced yield. (3)properly use of desuphurization byproduct was not led to heavy metal enrichment in radish crop, showed that it can't influence the security of farm product.