A sphygmomanometer with an accessory low-speed pressure release device comprises: a main body, having a multi-channel pipeline, and a pressure pump coupled to the multi-channel pipeline a circuit device, including a microprocessor and a pressure sensor, and the pressure sensor is coupled to the multi-channel pipeline, and the circuit device is coupled to the pressure pump through an electric circuit a cuff device, coupled to the multi-channel pipeline through an air channel and an accessory low-speed pressure release device, installed on the air channel and disposed outside the main body, so that the accessory low-speed pressure release device is adjusted according to the cuffs of different sizes and operated at an optimal air release speed to obtain measurements more quickly and accurately when cuffs of different sizes are used.
