Flame retardant composition for wood, flame retardant wood, and method for manufacturing the same

A flame-retardant composition for wood, comprising boric acid, ammonium phosphate dibasic, ammonium borate octahydrate, sodium borate, and a solvent, wherein the solvent is water, and, wherein the flame-retardant composition comprises 0.4 wt % to 1 wt % of boric acid, 3 wt % to 6 wt % of ammonium phosphate dibasic, 1 wt % to 5 wt % of ammonium borate octahydrate, and 0.5 wt % to 3 wt % of sodium borate.