Ultrathin plate pulse laser welding method

The invention discloses an ultra-thin plate pulse laser welding method, which comprises the following steps that: a pulse fiber laser is adopted to emit a laser beam, the pulse fiber laser is electrically connected with a laser head, the laser head comprises a galvanometer system, and the laser beam deflects through the galvanometer system of a swinging laser head to form a plurality of swinging modes; the laser beam forms different laser spot moving paths through different swing modes to weld the ultrathin plate; the welding width is increased by controlling the swing frequency and the swing amplitude in the welding process. A laser beam swings, during welding, due to the stirring effect of a key hole, a molten pool forms turbulent flow, growth of columnar crystals in a pasty area is destroyed, formation of isometric crystals is promoted, aggregation of low-melting-point eutectic crystals is hindered, the isometric crystals are evenly distributed in a weld joint structure, and weld joint hot cracks are preve