The invention relates to an ion chromatography-binode electrochemical hydride generation atomic fluorescence on-line combined system, which comprises a liquid chromatography pump, an admission valve, an ion chromatographic column, a three-way connecting device, a peristaltic pump, a binode electrochemical hydride generator, a four-way connecting device, a gas-liquid separator and an atomic fluorescence photometer. Element compounds of different forms in a sample are separated on the ion chromatographic column, the separated components are reduced to gaseous hydride on the binode electrochemical hydride generator, the gaseous hydride after undergoing gas liquid separation through the gas-liquid separator is led into the atomic fluorescence photometer by carrier gas for detection, and signals are recorded and processed by a self-developed work station. The ion chromatography-binode electrochemical hydride generation atomic fluorescence on-line combined system successfully realizes effectively converting the element compounds of different forms separated by the ion chromatographic column into hydride on line, and introduces an atomic fluorescence detection system on line, thereby establishing a simple, quick, sensitive, accurate, economical and reliable new technologic platform for element form analysis.