Abstract: An unpowered pressurized chlorine dioxide automatic generating and mixing disinfection device having a first raw material tank, a second raw material tank, a reactor, a water injector and a check valve; the first and the second raw material tanks and the reactor are sealed container on which there are raw material inlets and discharge holes, one raw material inlet is connected to the first raw material tank by a first pick-up tube which connects with a first titration valve, the other is connected to the second raw material tank by a second pick-up tube which connects with a second titration valve; the reactor discharging hole is connected to the water injector inlet, the check valve is installed in the connecting pipe.