The utility model discloses an automatic soldering tin robot, including weld assembly and xi si positioning mechanism, the weld assembly includes first driving piece, welding piece and first connecting piece, tin silk positioning mechanism includes tin silk pipe, second connecting piece and third connecting piece, the welding piece passes through first connecting piece with first driving piece is connected, the second connecting piece sets up on the welding piece, the third connecting piece does not set up along the direction of height slidable ground of welding piece on the second connecting piece, tin silk pipe rotationally sets up on the third connecting piece. The utility model provides an automatic soldering tin robot not only can realize the transform of arbitrary angle degree, can prevent to weld high -speed an impact moreover and treat weld workpiece and cause the damage to the work piece, the tin silk can be fixed a position the welding spare head that welds on the piece accurately and eaten tin point simultaneously, has improved welding quality.