A blood pressure measuring auxiliary device, a blood pressure measuring apparatus and a design method therefor are provided. During a blood pressure measurement, the measured pressure values and beating sound are recorded, so that the recorded pressure values and sound may be played back, which improves the accuracy of the auscultatory method and the parameters used in the oscillometric method may be adjusted, which improves the accuracy of the oscillometric method. The blood pressure measuring auxiliary device is arranged so that it can be connected with a pressuring device of a sphygmomanometer (5), and comprises a sensing module (1), a communication module, and an audio collection module (2). The sensing module (1) is used for sensing the pressure at the joint between the blood pressure measuring auxiliary device and the pressuring device and outputting a pressure signal to the communication module. The communication module is used for receiving the pressure signal to be transmitted thereby to a terminal apparatus (6). The audio collection module (2) is used for collecting the sound at a measured site and outputting an audio signal to the terminal apparatus (6).
