Multi-PH value system detecting system is maked with AT89C52 MCU as the control center. Detecting uses pH-BTA sensor, signals are amplificated through CA3140, ADC0808 realizes A/D conversion, 74LS148 controls 8 signals acquisition, 1602 LCD displays PH value, remote data monitoring in PC is realized through serial port. Adopt VB to monitoring interface in PC. Physical production and debugging is accomplished based on the simulation in proteus, 8 pH values of real-time and cycle monitoring system is realized ultimately. Actual test data shows that the error of measuring pH value and theoretical pH value is between ± 0.1 relatively.