The cell-free DNA storage tube can be directly used for blood collection and transportation, and stabilize the cell-free DNA in it. The storage solution is composed of EDTA anticoagulant and special protective agent, which can effectively inhibit the nuclease in plasma and prevent cells from releasing genomic DNA. This product is suitable for NIPT and early diagnosis. Cf-DNA can be extracted from blood samples in cf-DNA storage tubes, and the extracted cf-DNA can be used for downstream detection and analysis. At the same time, the product can also be used for the preservation of genomic DNA in blood nucleated cells.