Abstract: With the leap from current monitoring to early warning and traceability monitoring in water environment monitoring, Improving the ability of water pollution warning and tracing has become an important component of building water environment monitoring system. The online fluorescence fingerprint warning and tracing system for water quality is key equipment for quickly and accurately realizing water pollution warning and tracing, The accuracy and reliability of its performance directly affect the effectiveness of the detection results. Regarding the current lack of national metrological technical specifications for effective traceability of online water quality fluorescence fingerprint traceability systems in China, In order to improve its traceability system and ensure the accuracy of water environment pollution monitoring results, This article introduces the calibration method of the online water quality warning and traceability system based on its structure and working principle, Calibration projects such as signal-to-noise ratio, zero drift, range drift, repeatability, measurement linearity, and detection limit are proposed. At the same time, calibration examples and the evaluation process of uncertainty in detection limit measurement results are provided. The signal-to-noise ratio S/N is 259.91; The measured linear correlation coefficient is 0.9986; The limit of detection is 0.0017 mg/L with an expanded uncertainty to be 0.0010 mg/L（k=2）; Zero drift is 0.19%; Range drift is 0.40%; The measurement repeatability is 2.15%. The results indicate that this calibration method can accurately and reliably evaluate the comprehensive performance of the online water ripple warning and traceability system, and the calibration process and uncertainty assessment examples can provide reference for the calibration work of related instruments.