A needleless connector module, including: a flow guiding member having a flow guiding channel connecting to a upper portion of the flow guiding member, the upper portion including an ultrasonic welding portion thereon； an elastic valve； and a sleeve tube having an inner annular bottom surface formed on an inner wall of a base portion of the sleeve tube, an limiting portion of annular wall being defined by the inner wall of the base portion, the sleeve tube is sleeved on the elastic valve and assembled with the flow guiding member to allow the inner annular bottom surface to contact with the ultrasonic welding portion and let the limiting portion of the annular wall annularly cover a base side portion of the flow guiding member, so as to improve success of ultrasonic welding between the ultrasonic welding portion and the limiting portion of annular wall.
