In order to determine more appropriate conditions for diffusion gradient in thin-films technique,through the measurements of Cu2+ diffusion coefficient under different conditions(pH,ionic strength,temperature),the paper discussed the performance of DGT in pH and ionic strength,temperature aspects by the CMC,PAAS and PSS for the combination phase,found out the DGT performance was relatively stable,only the ionic strength with significant impact,other factors had little effect on the performance of DGT.