A movable welding flux tray comprises a welding flux recycling tray fixed to the upper end of a hydraulic lifting cart. A welding flux box is arranged on the lower side of one end of the welding fluxrecycling tray. A filter sieve is arranged at the upper end of the welding flux box. A rack is fixed to the upper end of the welding flux recycling tray. The rack is provided with two belt rollers through two roller shafts. The two roller shafts are provided with shaft clamps. The two belt rollers are connected through a welding flux conveying belt. The welding conveying belt sleeves the two beltrollers. A welding flux hopper is arranged on the upper side of one end of the welding flux conveying belt. The welding flux hopper is fixed to the rack. Compared with a traditional welding flux pad,welding flux pad wheel bearings and bearing blocks are eliminated, the shaft clamps with the simpler structure are adopted to limit the axial and circumferential freedom degree of the belt rollers, the cost is greatly reduced, the structure is simpler, and the manufacturing cost is lower.