Abstract: Seepage flow monitoring is an important project of dam safety monitoring. At present,manual measurement method is mainly used to monitor the seepage flow less than 1 L/s,which is time-consuming and laborious,and cannot realize remote online real-time monitoring.Therefore,a small flow automatic online monitoring seepage flow meter based on volumetric measurement principle is designed. Through the design of the measuring circuit,the influence of the structure of the instrument on the stability of the measuring device is avoided. Manual comparative measurement proves that the instrument has the characteristics of high measurement accuracy and long-term stability. It is suitable for the automatic on-line monitoring of dam seepage in small flow,multi-impurity and humid environment. It saves manpower and material resources and has good application value.