The invention discloses a medical ultrasonic antibacterial coupling paste and a preparation method thereof and relates to the technical field of ultrasonic imaging agents. The medical ultrasonic antibacterial coupling paste consists of the following components in percentage by weight: 1-5% of coagulated polysaccharide or a soybean fibrous protein collagen hydraulic substrate, 5-10% of glycerinum,3-5% of collagen, 0.05-0.5% of triclosan or chlorhexidine, 0-0.01% of a pigment, 0.2-0.5% of a preservative and the balance of pure water. The medical ultrasonic antibacterial coupling paste is transparent, soft, bendable, stable and degradable aqueous macromolecule gel and has the characteristics of high conductivity, relatively clear imaging, capability of effectively prolonging the service lifeof an ultrasonic probe, sterilization functions, cross pollution prevention, skin care, environment protection and sanitation and use convenience.