Cu-SAPO-34 catalysts with three different Cu contents (0.6 wt%, 1.1 wt% and 1.9 wt%) were prepared via one-pot synthesis method. Cu-SAPO-34 with Cu content at 1.1 wt% was found to be the best catalyst when considering both low temperature activity and high temperature stability. Then an economical and green way was attempted for the synthesis of Cu-SAPO-34 catalysts by recycling waste mother liquids. The synthesized samples were characterized by XRD, BET, SEM, NH3-TPD, H-2-TPR, and EPR. It was found that, after three recycles of mother liquids, the one-pot synthesized Cu-SAPO-34 catalyst exhibited high crystallinity, textural properties, acidity, and available copper, as well as superior catalytic activity for the selective catalytic reduction of NO with NH3 as compared to the initial Cu-SAPO-34 catalyst.