This paper first introduces the measurement of the core components of the thermal conductivity sensor used in nitrogen, and the influence of measuring thermal conductivity of nitrogen analyzer detection accuracy are analysed, then for each of the possible causes of low accuracy put forward concrete improvement methods, through improvement on the design and implementation of each item, finally the various parts of the application of improved measuring instrument of nitrogen, measured by the corresponding signal through the experiment of measuring speed and precision are analyzed and compared. Experiments show that the measurement of nitrogen side speed of improved faster and more accurate, practical and feasible improvement scheme.