The invention provides a method for performing automatic optimization according to different characteristics of tissue. The method comprises steps as follows: acquiring PC data; calculating all key values which have different horizontal depths and are used for judging different tissue characteristics according to the acquired PC data; judging corresponding tissue according to relations among all the key values line by line in the depth direction, and calculating the amplitude deference for each depth according to the characteristics of different tissue to form an amplitude difference curve (deltgc); calculating an optimized gain curve (New_TGC) according to the amplitude difference curve and a gain curve before system optimization. The invention further provides a corresponding device and a corresponding system. Automatic optimization can be performed according to the different characteristics of the tissue with the method.