A needleless connector module comprises: a sleeve tube, an elastic valve, and a flow guiding unit. The elastic valve sleeves an upper guiding tube of the flow guiding unit. A hollow shoulder portion of the elastic valve abuts a slanted retaining wall of the sleeve tube. Under a first usage condition, the hollow head portion of the elastic valve encloses the upper guiding tube narrow portion, hiding the first guiding opening in the airtight seam. Under a second usage condition, an injection tube presses the top face of the elastic valve, a hollow head portion of the elastic valve presses downward, driving the valve inner wall to abut a waist platform formed on the guiding tube, such that the first guiding opening is exposed outside the airtight seam, and such that the first guiding opening is connected to an injection opening of the injection tube.
