Bidirectional welding with trailing ultrasonic shock excitation device

The invention discloses a bidirectional welding with trailing ultrasonic shock excitation device. The bidirectional welding with trailing ultrasonic shock excitation device comprises a welding workbench, a platform traveling mechanism, a welding gun and three ultrasonic shock excitation devices, wherein the welding gun and vertical ultrasonic shock excitation device are arranged above a weld joint, the welding gun is located at the front, the vertical ultrasonic shock excitation device is located behind the welding gun, and the transverse ultrasonic shock excitation devices are arranged at two sides of the direction (transverse direction) vertical to the central section of the weld joint; in the welding process, the three ultrasonic shock excitation devices move synchronously along with the welding gun till all the welding is finished. According to the welding mode, the vertical ultrasonic shock excitation device carries out excitation oscillation on weld joint metal at a low-plasticity zone to lower the welding stress and deformation in the welding process, and meanwhile, the two transverse ultrasonic shock excitation devices exert transverse extrusion strain to condensed weld joint metal located at a brittleness temperature zone behind a molten bath to counteract the inherent splitting tensile strain of the weld joint to eliminate hot crack.