The invention discloses a novel method for extracting vanadium pentoxide from stone coal-vanadium ore, which comprises the following steps: the stone coal-vanadium ore is crushed, then is directly added with water for wet ball milling, and then is sent into a reaction kettle to stir to leach through acid adding and pressurization, leaching pulp is subjected to solid-liquid separation to obtain leachate, the leachate is pretreated and then is extracted, concentrated and purified, a strip liquor after the extraction is used to precipitate ammonium poly-vanadate, and then a vanadium pentoxide product is obtained through the thermolysis. The method has the advantages of high automation degree of production process, convenient operation, and steady and reliable operation; the yield of vanadium is more than 75 percent, the production cost is lower than those of a sodium method and a normal pressure acid leaching method, the consumption of sulfuric acid is only one third of that of the normal pressure acid leaching method, the grinding of ores adopts a wet ball mill; the method does not bake, has no pollution to the environment, fully utilizes mineral resources and thermal energy, shortens more than one time of leaching time, saves the thermal energy, and reduces the cost; the production process can not destroy the carbon content in the stone coal-vanadium ore, and leaching residue can be used for generating electricity, producing cement, baking bricks and tiles and so on.