The invention relates to a double-laser-beam welding method, in particular to a double-laser-beam welding method for reducing welding hot cracks of a T-shaped joint. The double-laser-beam welding method for reducing the welding hot cracks of the T-shaped joint aims to overcome the defect that the hot cracks of the T-shaped joint are generated after laser double-side synchronous welding is conducted. The double-laser-beam welding method for reducing the welding hot cracks of the T-shaped joint comprises the steps that firstly, two symmetrical arc grooves which are identical in size are machined on the two sides of the median line of the upper surface of a cushion plate correspondingly; secondly, skin is placed on the cushion plate, the to-be-welded position is made to coincide with the median line of the cushion plate, a stringer is placed at the to-be-welded position of the skin, two pressing wheels are symmetrically placed on the two sides of the stringer, and the vertical central plane of each pressing wheel coincides with the vertical central plane of the arc groove corresponding to the pressing wheel; and thirdly, double-laser-beam welding is conducted on the stringer and the skin, wherein the horizontal median line of each pressing wheel and the horizontal median line of the corresponding laser beam are located on the same plane, double-side laser wire-filling synchronous welding is conducted on the stringer and the skin, and symmetrical welding joints on the two sides are obtained after welding. The double-laser-beam welding method for reducing the welding hot cracks of the T-shaped joint is used for double-laser-beam welding of the T-shaped structure.