Abstract: A method of manufacturing inorganic binder by reduction furnace slag includes a raw material preparation step, a stirring step, a maintaining step and a drying step. The raw material preparation step is to provide a powder mixture containing 30 wt % to 55 wt % of reduction furnace slag, and 45 wt % to 70 wt % of glass powder. The stirring step is to place the powder mixture in a mixing tank, and add an alkali activator to the mixing tank to stir and react to form mixed slurry. The alkali equivalent (AE) of the mixed slurry is 2% to 7%, and the water-binder ratio is 0.25 to 0.4. The maintaining step is to place the mixed slurry in a high-temperature and high pressure maintaining environment for a maintaining time to get a binder. The drying step is to dry the binder.