Abstract: In response to the challenges encountered in the detection of total nitrogen in soil by continuous flow analyzer, a motor-driven shaft rotation module has been developed. The module allows the mixture of samples, reagents and air to be maintained within an appropriate temperature range for neutralization reactions, which was conducive to the detection and analysis of samples under optimal conditions by continuous flow analyzer. It reduced the limit of detection of total nitrogen from 16.4 μg/L to 10.0 μg/L, thus improved the analytical accuracy of the continuous flow analyzer for the samples.