The utility model relates to an automatic exhaust dispensing needle, it includes pjncture needle, syringe needle seat, exhaust steel needle, helmet, pjncture needle fixed mounting on the syringe needle seat, be equipped with on the pjncture needle business turn over medicine side opening and with the syringe needle seat on the centre bore of through -hole intercommunication, be equipped with business turn over gas side opening on the exhaust steel needle, rear end and syringe needle seat fixed connection are installed in the pjncture needle centre bore in the rear portion embedding of exhaust steel needle, be equipped with the gas vent with the steel needle intercommunication that exhausts on the syringe needle seat, install the exhaust filtration membrane that blocks water on the gas vent. The utility model discloses can self -bleeding among the medicine dispensing process to balanced liquid medicine bottle internal pressure. Its simple structure, equitable, operation, convenient to use, dispensing efficiency is high, has reduced the exhaust and has polluted the chance, has avoided the liquid medicine extravagant, can together close kind of model syringe and use.