1. An ultrasonic imaging method, comprising: inputting an echo strength at a specified point of an input image, the echo strength being used as a function input, dividing the function input with a fuzzy membership degree according to p intervals divided on a basis of the echo strength, and obtaining a space fuzzy segmentation array V at the specified point, wherein V=[V 1 , V 2 ,. .. , V p ], the values of V 1 , V 2 ,. .. , V p are between 0 and 1, and V 1 +V 2 +. .. +V p ≈1; determining a manipulated variable vector U for the specified point according to an input image content-based self-adaptive calculation or a user-based input, the manipulated variable vector U being sum of any combination of vectors selected from: local gain adjustment vector ULGA, high saturation suppression vector UHSS, low echo recovery vector ULER, and brightness equalization vector UBE, wherein ULGA=[ULGA 1 , ULGA 2 ,. .. , ULGA p ], UHSS=[UHSS 1 , UHSS 2 ,. .. , UHSS p ], ULER=[ULER 1 , ULER 2 ,. .. , ULER p ], UBE=[UBE 1 , UBE 2 ,. .. , UBE p ]; and calculating an inner product according to the space fuzzy segmentation array V and the manipulated variable vector U to obtain echo increment ΔI at the specified point, adjusting the echo strength at the specified point with the echo increment ΔI, and taking the adjusted echo strength as an echo strength at a corresponding point in an output image, wherein ΔI=U T ·V, U T denotes a transposed matrix of U.