The utility model relates to the technical field of electrolysis equipment, in particular to a large-particle diamond electrolysis device, which comprises an electrolytic cell, a cathode and an anodeare arranged in the cell body, the anode is connected with a positive electrode of a power supply, the cathode is connected with a negative electrode of the power supply, the positive electrode is a graphite plate, and the cathode is a steel plate. The method is characterized in that the method is characterized by comprising the following steps; a groove for placing the synthesis block is formed in the side surface, opposite to the cathode, of the anode; a synthetic block to be electroplated is clamped around the interior of the groove; wherein the groove is a cylindrical groove; the inside ofthe groove is a circular surface; the grooves are arranged in a plurality of rows and a plurality of columns; the depth of the groove is larger than the thickness of a synthetic block to be electroplated, the inner side face of the groove is provided with a blind hole, a spring is arranged on the inner side face of the blind hole, and when the synthetic block is placed in the groove, the spring abuts against the side face of the synthetic block, so that the large-particle diamond electrolysis device has the advantages that the effect of separating diamonds from the synthetic block is good, and electric power is saved.