The invention provides an extraction method for extracting vanadium pentoxide from low grade oxidized type navajoite. The method is as follows: crushing and grinding raw ores of the oxidized type navajoite, grading the crushed and grinded raw ores into coarse fraction products and fine fraction products; selecting mineral containing vanadium from the coarse fraction products by flotation to obtain vanadium concentrate, combining the fine fraction products with the vanadium concentrate to service as bulk concentrate, and taking the underflow of flotation as final tailings; drying the bulk concentrate, adding CaCO3 into the dried bulk concentrate, evenly mixing the CaCO3 with the bulk concentrate, placing the mixture into a disk granulator for pelletizing, leading particles into a rotary kiln for roasting, discharing and cooling calcined ores, leading the calcined ores into a lattice ball mill for wet grinding, levigating ore pulp, adding sulfuric acid the calcined ore quantity of which is 3%-5% into the ore pulp, performing agitation leach in an agitator bath for 4-6h, keeping the pH value within 2.0-2.5, leading lixivium produced by filtering the ore pulp to the purification procedure, washing leaching residues for three times so as to be prepared into building materials, and performing purification, resin adsorption, resolving, vanadium sinking and roasting on the lixivium to obtain a vanadium pentoxide product. The process of the invention adopts a technique of preparing with low cost, thereby effectivly improving the grade of vanadium raw materials, lowering the production cost and solving the problem of enviromental pollution.