Body fluid collecting device

The invention belongs to the technical field of medical instruments, and provides a body fluid collecting device which comprises an outer tube used for containing filtered body fluid, an inner tube used for containing unfiltered body fluid and a filtering component used for filtering the body fluid in the inner tube and then guiding the body fluid into the outer tube, and the filtering component can filter out specific components (such as human nucleic acid and nucleated cells) from the body fluid. A better analysis or detection effect is realized; after the inner pipe is connected with the base, the distance between the lower end of the inner pipe and the base is smaller than the thickness of the filtering component, so that the filtering component is pressed and limited on the base, the filtering component can be effectively fixed, and a filtering membrane is prevented from collapsing; after the inner tube and the base are detached, the filtering part is convenient to take out, taking of the collected body