A nozzle adapter configured to be connected with a Presta valve, said nozzle adapter comprising a connection seat including an imaginary axis line defined on a center of the connection seat, an inlet defined on a first end of the imaginary axis line, an outlet formed on a second end of the imaginary axis line, an air stop ring received in the outlet, a conduit defined between the inlet and the outlet, an engagement position defined in the conduit, a coupling slot defined on the connection seat, and a stopping means formed outside the coupling slot, the coupling slot having at least one controlling trench defined outside the conduit, wherein the at least one controlling trench extends to the engagement position via the inlet, and a respective controlling trench has a rotatable portion extending to the outlet adjacent to the air stop ring; at least one control element accommodated in the at least one controlling trench, wherein a respective control element has a fixing shaft extending on a first end thereof and connected with the rotatable portion, such that the at least one control element is adapted to swing along the fixing shaft arcuately, the respective control element has an engaging portion extending from a second end thereof and has a controlled portion, wherein the engaging portion is toothed and extends out of the engagement position; at least one returning element arranged on the at least one control element so that the engaging portion is pushed into the engagement position; a seal cover fixed outside the coupling slot of the connection seat, and defining an airtight space in the coupling slot by mating with the stopping means; and a controlling means mounted on a center of the connection seat opposite to the inlet and in the conduit of the airtight space is adapted to move with the controlled portion, wherein the controlling means extends out of the connection seat and is configured to be switched manually, when the controlling means is switched manually, the controlled portion is moved so that the engaging portion of the respective control element moves outward away from the engagement position; wherein the Presta valve includes an inlet portion, a screwing portion, and a neck portion, wherein the Presta valve is adapted to be inserted into the outlet, the neck portion of the Presta valve is adapted to be engaged matingly by the air stop ring, and the screwing portion is adapted to be engaged by the engaging portion at the engagement position, wherein the screwing portion is adapted to move forward from the outlet to the inlet. a connection seat including an imaginary axis line defined on a center of the connection seat, an inlet defined on a first end of the imaginary axis line, an outlet formed on a second end of the imaginary axis line, an air stop ring received in the outlet, a conduit defined between the inlet and the outlet, an engagement position defined in the conduit, a coupling slot defined on the connection seat, and a stopping means formed outside the coupling slot, the coupling slot having at least one controlling trench defined outside the conduit, wherein the at least one controlling trench extends to the engagement position via the inlet, and a respective controlling trench has a rotatable portion extending to the outlet adjacent to the air stop ring; at least one control element accommodated in the at least one controlling trench, wherein a respective control element has a fixing shaft extending on a first end thereof and connected with the rotatable portion, such that the at least one control element is adapted to swing along the fixing shaft arcuately, the respective control element has an engaging portion extending from a second end thereof and has a controlled portion, wherein the engaging portion is toothed and extends out of the engagement position; at least one returning element arranged on the at least one control element so that the engaging portion is pushed into the engagement position; a seal cover fixed outside the coupling slot of the connection seat, and defining an airtight space in the coupling slot by mating with the stopping means; and a controlling means mounted on a center of the connection seat opposite to the inlet and in the conduit of the airtight space is adapted to move with the controlled portion, wherein the controlling means extends out of the connection seat and is configured to be switched manually, when the controlling means is switched manually, the controlled portion is moved so that the engaging portion of the respective control element moves outward away from the engagement position; wherein the Presta valve includes an inlet portion, a screwing portion, and a neck portion, wherein the Presta valve is adapted to be inserted into the outlet, the neck portion of the Presta valve is adapted to be engaged matingly by the air stop ring, and the screwing portion is adapted to be engaged by the engaging portion at the engagement position, wherein the screwing portion is adapted to move forward from the outlet to the inlet.