The invention provides an integrated valve for an oxygen bottle of an oxygen breathing device. A cut-off pressure reducing valve assembly, an inflation assembly, a safety valve assembly, a pressure meter assembly and an output connector are installed on a valve body. The valve body is provided with a main channel, a cut-off pressure reducing channel, an inflation channel, a safety channel, a pressure detecting channel and an air output channel. The cut-off pressure reducing channel, the inflation channel and the pressure detecting channel communicate with the main channel. The air output channel communicates with a lower end opening of the cut-off pressure reducing channel. The cut-off pressure reducing valve assembly is installed in the cut-off pressure reducing channel. The inflation assembly is installed in the inflation channel. The safety valve assembly is installed in the safety channel. The pressure meter assembly is installed in the pressure detecting channel. The output connector is installed in the air output channel. According to the integrated valve, by means of the manner of combining a cut-off valve and a pressure reducing valve in the integrated valve, the cut-off valve and the pressure reducing valve do not need to be designed independently, only one valve is used for achieving functions of the cut-off valve and the pressure reducing valve, the size is small, and the weight is low.