According to the present invention, a method for preparing dried sweet potatoes comprises: an ingredient preparing step of preparing sweet potatoes, kelp, sugar, and salt； a washing and peeling step of washing and peeling the sweet potatoes； a first steaming step of steaming the sweet potatoes with steam generated from purified water in which the kelp is immersed and boiled； a first cooling step of cooling the firstly steamed sweet potatoes； a cutting step of cutting the cooled sweet potatoes into a predetermined size； a first drying step of drying the cut sweet potatoes； a second steaming step of adding more purified water to the purified water having the kelp contained therein which was used in the first steaming step, and steaming the sweet potatoes with steam generated from the purified water； a second cooling step of cooling the secondarily steamed sweet potatoes； and a second drying step of drying the cooled sweet potatoes, thereby completing the dried sweet potatoes by sequentially conducting the steps. According to the present invention, the dried sweet potatoes may be beneficial to the bone health since the kelp contains a great amount of magnesium and potassium.상기한 목적을 달성하기 위한 본 발명에 의한 고구마말랭이 제조방법은, 고구마와, 다시마, 설탕 및 소금을 준비하는 재료준비단계와, 고구마를 세척한 후 탈피하는 세척및탈피단계와, 정제수에 다시마를 담근 상태로 끓여 발생한 스팀으로 고구마를 증숙하는 1차증숙단계와, 1차증숙된 고구마를 냉각하는 1차냉각단계와, 냉각된 고구마를 일정크기로 절단하는 절단단계와, 절단된 고구마를 건조하는 1차건조단계와, 1차증숙단계에서 사용한 다시마가 담긴 정제수에 정제수를 추가한 후 끓여 발생한 스팀으로 고구마를 증숙하는 2차증숙단계와, 2차증숙된 고구마를 냉각하는 2차냉각단계와, 냉각된 고구마를 건조하는 2차건조단계를 순차적으로 실시하여 고구마말랭이를 완성하는 것을 특징으로 한다.
