The invention provides a laser pulse welding method for a thin-wall aluminum alloy butt joint. The laser pulse welding method includes the steps that step 1, 5A06 aluminum alloy parts are subjected to acid pickling and oil stain removal; step 2, to-be-welded parts of the parts which are processed to reach the size precision is cleaned; step 3, the to-be-welded parts are assembled together in a butt joint mode through a positioning clamp, and the to-be-welded parts are clamped to a rotating device of a laser welding machine; step 4, a cavity is filled with back protection gas, and gas protection is conducted on the back face of a weld joint; step 5, a laser angle and a shielding gas direction and flow are adjusted, laser pulse welding process parameters are set, and a weld joint track is determined for laser welding; and step 6, after a tool is disassembled, the forming quality of the front and back surfaces of the weld joint is checked, and a surface oxide layer of the weld joint is polished. According to the laser pulse welding method for the thin-wall aluminum alloy butt joint, the butt welding of the thin-wall aluminum alloy can be achieved under appropriate technological parameters, a large heat affected zone and air holes generated during laser welding are avoided, the strength of the obtained butt welding joint is high, and the cavity has good pressure resistance.