Abstract: In order to utilize the abundant resources of crude salt，this article provided a process for the preparation of sodium bicarbonate by double decomposition method with sodium chloride and ammonium acid carbonate as raw materials.The results of orthogonal experiment demonstrated that the influences of various factors on the preparation yield were different.The sequence of effect was as follows：mass fraction of sodium chloride>reaction time>amount-of-substance ratio of sodium chloride to ammonium acid carbonate>reaction temperature.The reaction conditions were optimized and the optimum reaction conditions were determined as：mass fraction of sodium chloride was 25%，reaction time was 1 h，the amount-of-substance ratio of sodium chloride to ammonium acid carbonate was 1.5 and the reaction temperature was 30 ℃.This article also studied the influential rules of each factor on the reaction through single factor experiment.This method had the advantages of simple process，convenient operation，high utilization rate of raw material and non-contamination etc.Therefore，it has wide market prospect.