The invention discloses a welding guide mechanism capable of automatically moving. The welding guide mechanism comprises a transverse beam, a movement mechanism and a guide mechanism; an upper linear guide way is arranged on the upper surface of the transverse beam, side linear guide ways are arranged on the side faces, the guide mechanism is in left-and-right sliding connection with the upper linear guide way, and the movement mechanism is in left-and-right sliding connection with the side linear guide ways; and the movement mechanism is provided with an up-and-down stretchable extending-out base, and the extending-out base and the guide mechanism are in up-and-down movable clamping. According to the welding guide mechanism, automatic movement of the guide mechanism is achieved through the movement mechanism, automatic locking fixation of the guide mechanism is achieved, cost is low, the automatic degree is high, and movement is accurate.