The invention provides a six-axis tin soldering robot comprising a rack (1), an X-axis assembly (2), a Y-axis assembly (3), a ZR-axis assembly (4) and a tin soldering head (5), wherein the ZR-axis assembly (4) comprises an R shaft (4-1) and a synchronous pulley (4-2) fixedly arranged at the lower end of the R shaft (4-1); the synchronous pulley (4-2) rotates around the R shaft (4-1). The six-axis tin soldering robot also comprises an M-axis assembly (6) and an N-axis assembly (7), wherein an M shaft (6-1) is vertical to the R shaft (4-1); and an N shaft (7-1) is vertical to the R shaft (4-1) and the M shaft (6-1). The robot is additionally provided with the R-axis, M-axis and N-axis assemblies on the basis of the existing X-axis assembly, Y-axis assembly and Z-axis assembly, so that the tin soldering head connected with the N-axis assembly can realize multi-angle free rotation in a space, the six-axis free movement of the tin soldering head is realized, various different soldering requirements can be met, and the problem of inapplicability caused by different welded products is solved.