The invention relates to the technical field of machines, in particular to an automatic soldering tin machine. The automatic soldering tin machine comprises a base, and a rack, an X-axis soldering tin mechanism, a Y-axis soldering tin mechanism, a Z-axis soldering tin mechanism, an automatic tin bar feeding mechanism, a rotation mechanism, a power mechanism and a control mechanism are arranged on the base; the rack is detachably connected with the X-axis soldering tin mechanism, the Y-axis soldering tin mechanism is in screwed connection with the base, the Z-axis soldering tin mechanism is arranged on the X-axis soldering tin mechanism and detachably connected with the X-axis soldering tin mechanism, the automatic tin bar feeding mechanism and the rotation mechanism are each detachably connected with the Z-axis soldering tin mechanism, the power mechanism is electrically connected with the control mechanism, the rotation mechanism comprises a rotation head and a welding gun, and the welding gun is in screwed connection with the rotation head. The soldering tin direction and the soldering tin angle of the welding gun are adjusted through the rotation mechanism, electronic elements nearby welding points are avoided, it is guaranteed that the electronic elements nearby the welding points cannot be scalded, the production efficiency of the products is greatly improved, the product quality can be guaranteed, and the full-automatic requirement is met.