The invention discloses a B-ultrasonic couplant bottle warm-keeping ring sleeve which is characterized in that a warm water interlayer is arranged between an inner container and an outer container, hot water is contained in the warm water interlayer, a hot water inlet and outlet is formed in the top of the warm water interlayer, the warm water interlayer is sealed by a sealing bottle cap, an inner cavity of the inner container is provided with a couplant bottle, the couplant bottle is contained in the inner diameter of the inner container, and a warm-keeping cloth layer is attached to the inner wall of the inner container. A warm-keeping cloth layer is arranged on the outer wall of the outer container. If the warm water interlayer is not filled with water, the warm water interlayer can also be provided with an electric heating tube and can also be filled with self-heating metal powder to generate heat energy to warm the B-ultrasonic coupling agent bottle. The coupling agent has the advantages of being reasonable and novel in design, simple in structure, easy to manufacture, convenient to use, free of side effects, free of irritation and untoward effects after being smeared on the skin, capable of protecting the skin, safe and reliable.