Total organic carbon content (Total Organic Carbon,TOC) in water is an important index for the classification of ultrapure water grades in experiments. Whether the measurement is accurate or not is related to the accuracy of the relevant experimental results. This paper designs a high-efficiency and high-precision ultra-pure water TOC detection equipment in view of the large volume of the oxidation tank in the existing TOC detection equipment based on ultraviolet oxidation method, which leads to the low oxidation efficiency of ultra-pure water, and most of them combine with NDIR sensors to detect carbon dioxide content and the introduction of complex process, which leads to the complex working process of the equipment and reduces the measurement accuracy and detection efficiency. In this paper, the ultraviolet oxidation method and the resistance method are combined, and an ultra-small volume and precise integrated oxidation-conductance tank is designed based on the structure of the oxidation tank. Based on high performance and low power embedded micro-controller, the hardware design and software development of electronic control system are carried out. Through a series of experiments, it is proved that the design has the characteristics of no pollution, low energy consumption, high efficiency, high precision and low cost while improving the detection rate.