The technology of measuring oil-water interface height in oilcan has always been a critical and extremely complex problem. This paper introduced a system for measuring oil-water interface height based on segmental capacitance sensor which is constructed by 30 parallel capacitors, which were connected to a switch to low capacitance measure circuit .The changes in capacitance were measured and then sent to IPC to find the height of oil-water interface. Finally, the oil-water interface height meters examination system was constructed in laboratory and experimental results show that the design basically achieved the desired objectives and requirements.