The utility model belongs to the technical field of the radiation source preparation, a a device for preparing large tracts of land radiation source is disclosed. The device mainly includes lift platform car, leveling platform, coating bath, plates the piece, plating bath bearer bar, power, plate the pen, plate a support and two -dimensional shift device, and wherein the bottom of lift platform car is provided with the gyro wheel, is provided with the rectangle lifter plate on the automobile body, the lifter plate top is arranged in to the leveling platform, and the bottom of leveling platform is provided with can finely tune high regulation foot, the coating bath is located leveling bench side for the long cubic of top open -ended form, and the size is not less than the size of plating the piece, it is the negative pole to plate the piece, lies in the coating bath, plates the negative pole that the piece passes through negative pole connecting wire and power and links to each other, and that plates the piece sets up the plating bath bearer bar all around, plating the pen and as the positive pole, plating a material and be graphite, it is located and plates a support below, it is connected with positive through the positive pole connecting wire to plate the pen, the device has good, the electric deposition efficiency of homogeneity height, easy operation and the lower beneficial effect that active regional area is big of cost.