The invention provides a blood pressure machine and a blood pressure calculation method thereof,The blood pressure machine is equipped with a pressurizing motor unit, which is connected with at least one vent valve unit and an air bag unit,The method comprises: controlling the pressurizing motor unit to pressurize the air bag unit;Measuring the measurement data of a pressurization section from the air bag unit during the pressurization process;Controlling the pressurizing motor unit to stop pressurizing the air bag unit,And controlling the air release valve unit to release the pressure of the air bag unit;Measuring the measurement data of a pressure relief section from the air bag unit during the pressure relief process;From the measurement data of the pressurization section and the pressure relief section respectively,Extracting at least one blood pressure parameter;And calculating to obtain an average value of one of the blood pressure parameters extracted from the pressure section measurement data and the pressure relief section measurement data,So as to obtain a blood pressure measurement result.本發明提供一種血壓機及其血壓計算方法，該血壓機配置一加壓馬達單元與至少一洩氣閥單元連通一氣袋單元，該方法包含：控制該加壓馬達單元對該氣袋單元進行加壓；在加壓過程從該氣袋單元量測一加壓段量測數據；控制該加壓馬達單元停止對該氣袋單元進行加壓，且控制該洩氣閥單元對該氣袋單元進行洩壓；在洩壓過程從該氣袋單元量測一洩壓段量測數據；分別從該加壓段量測數據與該洩壓段量測數據，提取至少一血壓參數；以及計算以獲得從該加壓段量測數據與該洩壓段量測數據所提取該血壓參數之一平均值，據以獲得一血壓量測結果。
