The invention belongs to radiation source preparation technologies and particularly relates to a regulating device for preparing a high-resolution alpha radiation source through a magnetohydrodynamics electrodeposition method. The regulating device structurally comprises a two-dimension positioning support and a permanent magnet regulating table top arranged on the two-dimension positioning support. The permanent magnet regulating table top comprises a base which is provided with a hole for fixing a deposition tank. A magnet fixing plate used for fixing a permanent magnet and a displacement drive device used for adjusting the position of the permanent magnet are arranged on the two sides of the hole. The upper portion of the two-dimension positioning support is provided with an electrode and an electrode rotary motor, and a controller for adjusting the electrode height and the rotation speed is arranged outside the two-dimension positioning support. An anode wire is installed at the lower end of the electrode. The center of the electrode is located over the center of the deposition tank fixing hole in the base of the permanent magnet regulating table top. According to the regulating device, conditions in the preparation process of the radiation source can be accurately adjusted and controlled, the deposition repeatability and operation safety can be improved, and meanwhile, the deposition efficiency and energy resolution of the radiation source are greatly improved.