The invention belongs to the filed of metal connecting, and particularly relates to a method for connecting low carbon steel with a red copper lead for an electrochemical corrosion test at low temperature. The method comprises steps of polishing a low carbon steel sample, washing, then preheating, heating the sample to 240 DEG C-260 DEG C by a heating plate, scattering a mixed soldering flux at the polished welding position of a mother material, continuously sending a brazing filter material into molten liquid drop of the welding position, directly inserting the red copper lead plated with soldering tin through immersion into soldering tin liquid drop of the welding position of the low carbon steel sample so as to be wetted to form an integral joint, and after complete solidification of the liquid drop, standing and cooling to room temperature so as to obtain the welded joint. Compared with traditional welding manner, the connecting method has the advantages of simple equipment, simple raw materials, simple and convenient processes, and low welding temperature; the welded joint obtained through the method has low resistivity and good repeatability.