The invention provides a needle-less positive pressure connector which is used in combination with an infusion instrument. When the needle-less positive pressure connector is used, along with the opening of a positive pressure connector rubber plug, unidirectional liquid flow is realized, so that cutting pollution which might be caused by needle puncture is prevented; when the infusion instrument is pulled down, the positive pressure connector generates positive pressure automatically making liquid in the positive pressure connector advance forward, so that backflow of blood is prevented and blocking of a remaining needle is prevented. The needle-less positive pressure connector is simple in structure, needs no extra parts and achieves a remarkable effect.