The invention discloses an
intravenous catheter locator, which mainly comprises a
syringe, a needle set and a push rod, wherein the needle set is provided with a positioning piece which is positioned in the
syringe, a needle seat which is limited between the positioning piece and the
syringe, a needle body which passes through the syringe, a
catheter seat which is sleeved on the syringe and a flexible
catheter which is jointed with the
catheter seat and allows the needle body to pass through. The needle seat is provided with a
cavity wall which defines a cavity and is used for observing the cavity. The push rod is provided with at least one vent port which is communicated with the outside air pressure and a connecting piece which is sleeved with the needle seat. When the vent port is closed to carry out a
testability phlebotomizing step, the circulating situation of back-flow blood in the cavity is observed through the
cavity wall. When the vent port is opened, the back-flow blood can be flowed into the connecting piece, and the displacement of the push rod can be used for starting the connecting piece so as to link the needle seat and the needle body to hide in the push rod.