of said bast fibres due to the high temperature during the process of health preservation to evaporate so that it can avoid too much water on the surfaces of the bast fibres so as to avoid the bast fibres of twisting with the rollers of machine during the process of spinning thereby improving the efficiency and quality of spinning as an optional step it can be skipped however in the preferred embodiment of health preserving bast fibres placement of bast fibres at room temperature had better be adopted the health preserving assistant after adding water is sprayed on jute fibres wherein the weight proportion of said health preserving assistant and water is 1 30 in one of the preferred embodiments during the process of spraying said health preserving assistant is sprayed on each layer of the jute fibres paved until finishing the paving of sufficient said jute fibres to be stored in the health preserving container wherein the weight proportion of said health preserving assistant and said jute fibres is 0 4 1 thereby providing sufficient said health preserving assistant to said jute fibres for health preserving then the paved jute fibres are placed in a first health preserving container for 2 5 days at this stage said health preserving assistant is ensured to slowly penetrate the fibres after that the.