The invention discloses an annealing and pickling method for duplex stainless steel. The method comprises the following steps that the duplex stainless steel subjected to cold rolling through a twenty-high roll mill is uncoiled, degreased, annealed in a continuous annealing furnace, pickled, leveled and coiled so as to obtain a finished product, wherein in the annealing step in the continuous annealing furnace, the annealing temperature is 800-1200 DEG C, the pickling step comprises the processes of primary sodium sulfate electrolysis, primary grinding and scrubbing, secondary sodium sulfate electrolysis, secondary grinding and scrubbing and mixed acid pickling, and scale is removed through the pickling step. The method has the advantages that the pickling step after annealing of the duplex stainless steel comprises the processes of twice neutral salt sodium sulfate electrolysis, twice grinding and scrubbing and mixed acid pickling, so that the scale on the surface of strip steel is removed, the concentration of HF used is low, the operation time is short, the production cost is saved, the safety of workers is protected, and the environment is protected.