The invention discloses a method for treating melamine byproduct ammonia water by utilizing ammonia synthesis raw gas. The method comprises the following steps: conveying the ammonia synthesis raw gasinto two sets of carbonization main towers in parallel through three sections of inlets of a compressor; carrying out bubbling reaction on the ammonia synthesis raw gas and high-carbonization-degreeammonia which is a melamine byproduct in the carbonization main towers, so as to generate an ammonium bicarbonate suspension solution; centrifuging and separating the suspension solution to prepare anammonium bicarbonate solid, reacted diluted ammonia water and reacted gas.