This invention relates to a method for producing low-zinc rongalite. The method comprises: mixing water and zinc powder, beating, adding SO2, reacting to obtain zinc hydrosulfite, placing in a reaction pot, adding formaldehyde and zinc powder, reacting to obtain alkaline sodium formaldehyde sulfoxylate, precipitating, removing the supernatant, adding NaOH, reacting to obtain sodium formaldehyde sulfoxylate, filtering, standing for settlement, cooling, adjusting the pH value, performing ultrafiltration, mixing, adding NaOH, sending into an evaporator, evaporating to obtain melt of low-zinc sodium formaldehyde sulfoxylate, cooling, solidifying, and pulverizing to obtain the final product. The obtained low-zinc rongalite can satisfy the requirements of pharmaceutical and plastic industries. The zinc content is less than or equal to 50 ppm. The low-zinc rongalite has such advantages as high purity, high stability, low production cost and convenient usage.