In the modern metallurgical industry, online analysis of converter flue gas is commonly conducted by laser absorption spectroscopy, which can only measure a single gas component by each sensor. Therefore, a combination of multiple sensors is usually needed to monitor multiple gases simultaneously, including CO，CO₂，O₂，H₂, etc. The whole analysis system is complicated and expensive, with a slow response speed. Daily calibration and maintenance are also time-consuming and labor-intensive. This manuscript established a novel Raman spectroscopy-based methodology for real-time and multi-component analysis of converter flue gas to simplify the online analysis system and improve the efficiency of online measurement and the steelmaking process. A multi-gas analysis system for fuel gas measurement was also developed for the first time. The content of five CO, CO₂, N₂, O₂, and H₂ components could be quantified simultaneously based on the characteristic peak intensities. With a detection range of 0.1%~100%, the RSD value of our method was ≤0.1%. In the analysis system, the sample gas processing module adopted a high-temperature resistant probe and a high-power suction pump, which can effectively and quickly remove moisture and dust from the sample gas entering the analyzer, ensuring stable testing conditions. The analysis module employed a narrow-linewidth 532 nm laser, a transmission grating spectrometer, and a free space light path design to improve the detection sensitivity for gas analysis. Compared with single-component analysis techniques, the multi-component analysis method proposed in this manuscript could provide quantitative results for five components simultaneously without being affected by gas pressure variation. Sample gas processing and system maintenance were simple, while the detection accuracy was high. When N₂ standard gas was measured, the intensity of the characteristic peak was stable, with fluctuation less than 0.48% within 24 hours. The detection error of our method was less than 0.3% when quantifying standard gas samples, meeting the requirements of real-time analysis of converter flue gas. The multi-component gas analysis method by Raman spectroscopy could be widely applied in both the metallurgical industry and other fields by simple model expansion.