Solder stick used for low temperature welding and preparing process of solder stick

The invention relates to a solder stick used for low temperature welding and a preparing process of the solder stick. An alloy for preparing the solder stick is characterized in that other alloys areadded into basic welding flux, the basic welding flux comprises the ingredients including, by weight percentage, 30%-60% of Bi, 0.01%-3.5% of Ag, 0-3.0% of In, 0.1%-5.0% of Sb, 0-0.025% of Ge, 0-0.10%of P, the other added alloys including one or more of Sc, V, Co, Ni, Zr and Mo, and the adding amount does not exceed 0.20% of the basic welding flux and the balance Sn. By means of the solder stickand the preparing process, microalloying is achieved for improving the molding performance of the solder alloy, and low temperature alloy solder for preparing the low temperature solder stick can be obtained. Meanwhile, the scientific and reasonable preparing process is adopted, and the low temperature welding solder stick which is good in plasticity, not brittle and high in quality is prepared. The process is simple and pr