The present invention relates to a method for preparing black salt. The black salt is prepared by: collecting seawater and adjusting the salinity thereof through heating in boiling water； inputting a native grass ingredient selected from Raisin tree leaves or fruits, mulberry, Rubus coreanus, blueberry, a plum concentrate, a red ginseng concentrate, a garlic concentrate, Ganghwa mugwort, and the like, which are useful for the health, Rehmannia glutinosa or licorice, and a seafood ink from squid, octopus, or webfoot octopus； installing a reducer for rotation at the inside； preparing black salt crystals by performing heating in boiling water through a crystallizing machine in which a reducer for rotation is installed and a filler fills between an inside and an outside of a reactor； and then freeze-drying the crystals without firing. Since a black salt crystallizing machine and a freeze-dryer are employed instead of melting of bay salt or color coating using medicine, a separate pulverizing procedure and a separate bittern remover are not necessary, thereby reducing the time and costs. Further, the prepared black salt contains a native grass ingredient useful for the health, thereby obtaining salt having low salinity and high mineral. [Reference numerals] (AA) Seawater； (S100) Seawater storage tank； (S200) Tranfer to dividing tanks； (S300) Adjust evaporative salinity； (S400) Native grass concentrator； (S500) Heat in boiling water at 30-60°；C； (S600) Input a concentrate of Rehmannia glutinosa or licorice and an ink from a squid, octopus, or webfoot octopus； (S700) Prepare black salt crystals； (S800) Perfrom Freeze-drying and natural drying본 발명은 흑염의 제조방법에 관한 것으로, 해수를 채취하여 중탕으로 염도를 조절한 후 건강에 유용한 헛개나무 잎 또는 열매, 오디, 복분자, 블루베리, 매실농축액, 홍삼농축액, 흑마늘 농축액, 강화쑥 등으로부터 선택되는 산야초 성분 및 숙지황 또는 감초 및 오징어, 낙지, 쭈꾸미 등의 수산물 먹물을 투입하고 내부에 회전용 감속기가 설치되고 반응기 내부와 외부 사이에 충진재가 주입된 결정체 기계를 통하여 중탕가열 하여 흑염결정체를 제조한 후 소성 없이 이를 동결건조하는 단계를 포함하여 구성되는 것을 특징으로 하며, 천일염을 녹이거나 약재를 이용하여 색채를 코팅하는 방법이 아닌 흑염 결정체 기계
