The electrolyzer adopts a 3ml thick beaker and puts it in a specially-made ventilated kitchen, and it works in the way of "two negative electrodes and one positive electrode". The cell conductor is made of pure silver with a diameter of 5mm (7mm is recommended), the cathode hook is made of 99.995% gold with a diameter of 4mm, the anode is made of coarse gold with a diameter of 4mm, and the cathode plate is made of 99.99mm thick, 12mm wide and 15mm long. The whole cathode weighs about 12g, the anode gold is 15mm thick, 12mm wide and 15mm long, and the ear semicircle is 15mm in diameter. It is cast by high-density graphite mold. The weight is about 4.65 kg, the content of electrolytic crude gold is about 99.3%, and the anode hook is 34 grams. Hang the anode on the anode hanging rod (Shi Ying glass rod), turn on the power supply, make the current stable at 265A, brush the anode once at 3 times of electrolysis, sink the silver chloride brush to the bottom of the cup, and continue electrolysis until the end, lasting about 6 hours, and the residual electrode weighs about 8 grams. Each cup is electrolyzed twice in 12 hours. In the second round of electrolysis, several electrolytic cells should be left according to the calculation ratio, and the electrolyte used in this shift should be recovered and cast together with the residual electrode for electrolysis, so that the extrusion of gold electrolysis per 1 kg is less than 3 kg. The produced electrogold is washed with hydrochloric acid in the electrolytic cell, then washed with water to form an acid-free ingot, and then subjected to secondary electrolysis under the same conditions. The obtained electrogold is boiled and washed with 2: 1 nitric acid for 2 minutes, with 2: 1 ammonia water for 2 minutes, and the ingot is washed with water, so that more than 99.995% gold can be obtained.