The utility model discloses an adjustable welding platform for an air-condition cross-flow fan blade welding machine. The adjustable welding platform comprises a base, a screw rod disposed on the base, a plurality of supporting rods fixedly disposed around the base respectively, a top plate fixedly disposed on end parts of the supporting rods, a plurality of guide rods fixedly disposed around the screw rod on the base respectively, a workbench is disposed on the guide rods through sliding fit and is provided with a screw hole, the screw rod passes through the screw hole in the workbench and threadedly fits with the workbench, a motor is disposed on the top plate and is in transmission connection with the screw rod, the workbench moves upwards and downwards along the guide rods as the screw rod rotates, a clamping seat is fixedly disposed on the workbench, and a welding machine with a welding gun thereof pointing at the clamping seat is disposed on the top plate. The adjustable welding platform is reasonable and reliable in structure and low in cost, and can not only meet welding requirements for air-condition cross-flow fan blades of different lengths, but also facilitate man-operated material feeding and taking, thereby raising welding precision and welding efficiency.