The utility model relates to a bracket device for welding a bus tube. The bracket device comprises a main bracket (11), a rotating roller bracket (12), a rotary transmission mechanism (15), a lifting mechanism (14), at least one rotating roller (121) and at least one pair of idle wheels (131), wherein two idle wheels in one pair of idle wheels (131) are in parallel and are connected to the main bracket (11) at the same axial height in a rotating manner to position and support the bus tube; the rotating roller bracket (12) is connected to the main bracket (11) in an up-down sliding manner; the lifting mechanism (14) is connected with the rotating roller bracket (12) to drive the rotating roller bracket (12) to slide up and down; the rotating roller (121) is supported against the rotating roller bracket (12) in the rotating manner and is in transmission connection with the rotary transmission mechanism (15) to perform axial movement transmission on the bus tube. The bracket device has the beneficial effects that the bracket device has a perfect function and a compact structure and can be excellently matched with the automatic performance of an automatic welding machine to realize better automatic performance.