The invention discloses a phosphate solubilizing bacterium and an extraction method thereof. The phosphate solubilizing bacterium is named a strain B5, the strain B5 is a pseudomonas bacterium, determination results of biochemical criterion are gram staining is negative, a methyl red test is negative, a V-P reaction is negative, an indole test is negative, an oxidase test is negative, the strain B5 can use citrate as a carbon source to produce extracellular enzyme-gelatinase liquidation gelatin, catalase and indole are produced, and H2S is generated; the order of the phosphate solubilizing ability of the strain B5 from high to low under different carbon sources is that glucose is greater than galactose, the galactose is greater than lactose, the lactose is greater than sucrose, and the sucrose is greater than soluble phosphate starch, and the order of the phosphate solubilizing ability under different nitrogen sources is that ammonium sulfate is greater than ammonium chloride, the ammonium chloride is greater than urea, and the urea is greater than potassium nitrate; and the optimum growth temperature of the strain B5 is 28-32 DEG C, and the optimum growth pH of the strain B5 is 7-9.