The invention discloses a cold-type casting welding method of roller necks, comprising: a procedure of adjusting the verticality of a cold-type neutral roller and fixing by an oblique iron, a fill forging process, a baking process, a mould assembling process, a wash melting process and a pouring process, wherein, in the fill forging process, the periphery of the roller neck on the oblique iron is filled and forged by water glass self-hardening sand until the height approaches to the height of the cross section of the roller neck; 1-4 layers of prefabricated fireproofing tiles are tightly arranged on the surrounding of the excircle of the roller neck; the end-face external diameter of the fireproofing tile is larger than the internal diameter of an overflow box; the upper flat surface of the fireproofing tile is lower than the cross section of the roller head; in the baking procedure, the water glass self-hardening sand automatically hardens for over 2 hours, and then the roller head fracture surface is baked and preheated by coal fire for 24 hours; and after the baking process is finished, the mould assembling process, the wash melting process and the pouring process are carried out. By the method provided by the invention, the defect of the air vents of the cast soldering products can be avoided, the casting quality is ensured, and the repair time of the roller is greatly shortened.