The invention discloses a radiating tube positioning assisting assembly applied to radiator core assembling. The radiating tube positioning assisting assembly comprises a rack, an assembling platform, a left mold worktable, a right mold worktable, a PLC, lifting platforms and a positioning mechanism, wherein the lifting platforms are arranged at two sides of the assembling platform, respectively, the positioning mechanism is arranged on the lifting platforms and comprises a plurality of comb tooth seats, a plurality of I-shaped heads, a comb tooth seat cylinder, a comb tooth seat fixing plate and a plurality of comb tooth pieces, a plurality of comb teeth are arranged on the comb tooth pieces at equal interval, the comb tooth pieces are embedded into the side ends of the comb tooth seats, comb tooth seat clamping rails are arranged on the comb tooth seat fixing plate, clamping slots are formed in the bottom of the comb tooth seats, and the comb tooth seats are clamped on the comb tooth seat clamping rails. The radiating tube positioning assisting assembly has a simple and reasonable structure, and as the comb tooth pieces are arranged in the side ends of the comb tooth seats, the smooth sliding of the comb tooth seats and the positioning precision of the comb teeth are prevented from being influenced by the fact that aluminum powder on radiator tubes falls between movable buckling parts of the comb tooth seats during tube dropping, and thus the machining precision and the percent of pass of products are enhanced.