The sphygmomanometer is an instrument for measuring peripheral blood pressure, and there are two types of sphygmomanometers: the auscultatory method and the sebo method. The auscultation method sphygmomanometer is further divided into manual auscultation method and automatic auscultation method. Blood pressure is the abbreviation for arterial blood pressure in the body circulation. Blood pressure is generated by the pressure acting on the walls of the blood vessels as the blood flows through them, and it is the driving force that pushes the blood forward through the vessels. When the ventricular portion of the heart contracts, blood is pumped from the ventricles into the arteries, and this is when the pressure of blood on the arterial walls is highest, called systolic pressure. When the ventricles are diastolic, the arterial vessels retract elastically, and the blood still slowly continues to flow forward, but the blood pressure drops, and the pressure at this time is called the diastolic pressure. The measurement principle of sphygmomanometer can be divided into two types: direct measurement method and indirect measurement method. The direct measurement method is also called invasive measurement, which is the blood pressure measured after a catheter is placed in the blood vessel through a puncture. Indirect measurements, also known as noninvasive measurements, are the various blood pressures measured on the body surface using various sphygmomanometers that are commonly seen in clinical practice.