The invention discloses a preserved roselle manufacturing method which comprises the following steps of preparing materials, salting the materials, protecting crispness of the materials, hardening the materials, sulphuring the materials, precooking the materials, sugaring the materials, drying the materials, reshaping the materials, packing the materials and the like. Roselle is salted to remove part of water, so that tissues of the roselle are compact, the permeability of cells is changed, and sugar can permeate into preserved roselle conveniently. Thus, the preserved roselle is pure in flavor, delicious in taste and convenient to eat. Furthermore, nutrients of the roselle are fully kept. The preserved roselle has the effects of relieving summer heat, reducing blood pressure, intensifying blood vessel elasticity, curing hypertension, clearing heat, detoxifying, helping digestion, helping produce saliva and slaking thirst.