NOVELTY - Extracting L-glutamine comprises e.g. culturing Corynebacterium glutamicum and Brevibacterium to bacterial solution, obtaining mixed bacteria solution, inoculating inoculum into the fermentation culture medium, fermentative culturing to obtain L-glutamine fermentation liquid, filtering, collecting filtrate and retentate, concentrating filtered liquid, crystallizing, collecting centrifugal mother liquid and crude product, adjusting pH of resulting solution, removing cation by cation exchange resin filter, collecting effluent liquid, adding activated coal and decoloring.    USE - The method is useful for extracting L-glutamine (claimed).    ADVANTAGE - The method has high fermentation efficiency, has simple extracting process, is environmentally friendly without pollution, and can convert waste into useful product.    DETAILED DESCRIPTION - Extracting L-glutamine comprises (i) culturing Corynebacterium glutamicum and Brevibacterium to bacterial solution with concentration of 1x 10asterisk8 cells/ml, according to volume ratio of 3:1, obtaining mixed bacteria solution, inoculating 3% inoculum into the fermentation culture medium, and fermentative culturing for 32 hours to obtain L-glutamine fermentation liquid, (ii) filtering L-glutamine fermentation liquid using micro-filter film, collecting filtrate and retentate, (iii) concentrating filtered liquid under vacuum condition, collecting concentrated liquid, crystallizing once the concentrated liquid, collecting centrifugal mother liquid and crude product, adding deionized water for dissolving the crude product, collecting the solution, adding deionized water at 40 degrees C, where the adding amount of water is 40% of crude product, (iv) taking step (iii) obtained resulting solution, adjusting the pH to 5-6, at 25 degrees C, removing cation by cation exchange resin filter, again by anion exchange resin to remove anion, collecting effluent liquid, (v) adjusting step (iv) obtained effluent pH to 6.5, at 35 degrees C, adding activated coal and decoloring, stirring for 1 hour, then using ultra-filter film for filtering to remove activated coal, collecting filter liquor, (vi) adding step (v) filter liquid into single-effect concentration pot and carrying out low temperature vacuum concentration, filtered liquid volume is 25%, collecting concentrated Liquid, taking concentrated liquid, cooling and crystallizing, reducing temperature per hour to 10 degrees C, and to 5 degrees C, maintaining for 20 hours, finally centrifuging, and drying to obtain finished L- glutamine, and (vii) mixing step (ii) retentate, step (iii) obtained mother liquid, humic acid, monoammonium phosphate, potassium chloride and urea uniformly, adding double-screw extruding granulator to carry out pelleting, then spraying microorganism preparation, stirring evenly, finally drying at 20 degrees C, controlling the water content at 5%, and obtaining fertilizer and packaging.