The tin-plated strip is heated by convection for Reflow treatment. After the treatment in the reflow furnace, the internal stress of the tin-plating layer on the strip can be released, the stability and durability of the tin-plating layer can be improved, the whisker phenomenon in tin-plating can be reduced, the surface quality of the tin-plated strip can be improved, and the performance and quality of metal products can be effectively enhanced.