Abstract: Synthesis method of ammonolysis precipitated silica was using ammonification agents，such as aqua ammonia or liquid ammonia as main raw material to react with the by-products（such as fluosilicic acid，ammonium fluorosilicate，silica  containing gel，and silica containing slag） of phosphate fertilizer industry to produce silica with ammonification precipitation process.It is a special synthesis method of precipitated silica formed with the generation of phosphate fertilizer industry waste containing fluorine and silicon in recent years.Reaction principle and research progress of ammonolysis precipitated silica were introduced.Methods of ammonolysis precipitation and traditional precipitation were compared on the aspects of reaction mechanism，cost of production，process-control，product quality，and environment effects etc.，and prominence was given to the merits of ammonolysis precipitation method.Finally，some suggestions for the development direction of precipitated silica in China were put forward.

Key words: ammonolysis, precipitation method, amorphous silica, phosphate fertilizer industry