Abstract: Black pearl was obtained by silver salt dyeing method. This inorganic method for preparation of black pearl was investigated and improved. The optimized dyeing condition of inorganic black dyeing process to prepare stable and durable black pearl using silver salt method was obtained by comparison experiments. The durability of inorganically dyed pearls was evaluated through sweat pH experiments. Among the dyeing methods for black pearl, the improved silver salt dyeing method is simple, with uniform and stable color, which has certain commercial value.