The invention relates to a method for extracting simple substance finished sulfur granules from sulfur concentrate, which adopts gravitational separation and membrane separation, liquid solid suspension is treated by rough filtration and fine filtration. The extracting process comprises the steps of: drying sulfur concentrate, continuously melting sulfur concentrate with a steam indirect heat exchange method in a sulfur melting kettle to enable simple substance sulfur to be melted to form liquid sulphur, stirring the molten sulphur liquid and solid particles in the sulfur concentrate to form liquid solid suspension, carrying out gravitational still separation for the liquid solid suspension under the action of height difference H which is 800 to 1000mm, forming supernatant liquid containing sulfur after separation, transporting the supernatant liquid to a membrane separation machine, carrying out liquid solid suspension under the action of the pressure difference which is 0.05 to 0.1MPa to achieve the purposes of fine filtration and purification, extracting sulphur liquid containing over 99% of simple substance sulfur, automatically flowing into a liquid sulfur tank, transporting sulphur liquid to a sulphur pelleter with a sulphur pump, and preparing finished sulfur granules.