The invention discloses a method for preparing filter material which can remove ferrous and manganese ions from underground water, which includes the following steps: (1) natural zeolite is soaked by 2-15% of sulfuric acid solution, washed with water and dried; (2) then the natural zeolite is soaked by sodium hydroxide, washed by water until the pH value reaches 8, and dried; (3) the natural zeolite is sintered to the temperature of 300-900 DEG C, cooled and washed with clear water, then is ready for use; (4)0.3-25% of sodium hydroxide solution and 7%-13% of potassium permanganate solution are added for soaking and then the sodium hydroxide solution and the potassium permanganate solution are drained; (5) 3-15% of aqueous ammonia is soaked and stirred; (6) the natural zeolite is washed byclear water until the pH value reaches 11, and dried to obtain the filter material. In the invention, the natural zeolite is adopted as raw material, sintered at high temperature, activated and modified; thus the natural zeolite is endowed with ion exchange property and can remove the ferrous and manganese ions from the underground water under the condition of no aeration; after regeneration, thefilter material can continue to be used, and has low cost, significant effect and long service life.