Air exhausting and pressure dropping structure for sphygmomanometer

The utility model relates to an air exhausting and pressure dropping structure for a sphygmomanometer, which is composed of a wrist belt and a sphygmomanometer. A circuit board is arranged in the sphygmomanometer and a pressure sensor is arranged in the circuit board; a sensing end hole is arranged on the pressure sensor and is connected with a circuit control unit; a microprocessor is arranged in the circuit control unit and is connected with a motor driving mechanism; the motor driving mechanism is connected with an inflation tube whose outlet is connected with an electricity reducing valve on which an air outlet hole is arranged; the air outlet hole and the sensing end hole are respectively communicated with the wrist belt; the sphygmomanometer is that the pulse which is output by the microprocessor controls circuit to make the action of the electricity reducing valve reduce the voltage to precisely measure the blood pressure.