According to the different contents both silicon tetrafluoride and hydrogen fluoride in production of phosphate fertilizer, they are absorbed with ammonium fluoride and/ or ammonia to obtain high concentration solution of ammonium fluosilicate, which is ammoniated and separated. 依据磷肥生产排出含氟废气中的四氟化硅和氟化氢含量的不同,以氟化铵和/或氨进行吸收,得到高浓度的氟硅酸铵溶液。