The blood pressure value is an important parameter to determine the patient's condition, thus a realtime noninvasive monitoring module for the continuous blood purification system application is designed in this work. To achieve a noninvasive realtime measurement of blood pressure in the circulation line, the monitoring module uses the gas pressure sensor as the detection of blood pressure, lowpower microcontroller MSP430F449 as the processing core and highprecision AD7714 as the analogdigital converter module. The experimental results show that the realtime blood pressure monitoring module can achieve accuracy of 0.12% , the input and output has good linear relationship, and can reflect the accurate changes of blood pressure in realtime.