The invention relates to a method for manufacturing fertilizer base materials from garbage containing organic matters. The method includes placing fed and screened garbage containing the organic matters into a flash evaporation blasting machine; filling steam into the flash evaporation blasting machine, controlling the temperature of the inside of the flash evaporation blasting machine to range from 210 DEG C to 230 DEG C, controlling the pressure of the inside of the flash evaporation blasting machine to range from 2Mpa to 3Mpa and controlling the holding time to last from 80 seconds to 100 seconds; completing flash evaporation blasting within 0.01 second so that muddy fertilizer base materials are manufactured from the pretreated garbage containing the organic matters; and placing the muddy fertilizer base materials into a drum dryer to dry the muddy fertilizer base materials, then feeding the dried fertilizer base materials into a cylindrical primary cleaning sieve and controlling the aperture of the cylindrical primary cleaning sieve to range from 10mm to 15mm. Undersize materials obtained from the cylindrical primary cleaning sieve is the finished fertilizer base materials. The method has the advantages of convenience in production, high operability, environmental protection and capabilities of implementing cyclic utilization and effectively solving problems of environmental pollution and ecological hazards caused by garbage.