Safe breathing system for hydrodynamic test

The invention relates to a safe breathing system for a hydrodynamic test, which mainly solves the problems of short gas supply time and inconvenience in movement of a worker in the existing mode that the worker carries an oxygen bottle on the back to supply gas. Comprising a high-pressure breathing air compressor, a filtering system, a high-pressure pressure reduction system, two air bottle switches, a plurality of breathing air pipes, a plurality of pressure reducers, a high-pressure air bottle set and a plurality of breathing masks. The filtering system is connected with the high-pressure breathing air compressor through an air supply pipe; the filtering system is connected with the high-pressure decompression system through a gas conveying pipe; the high-pressure gas cylinder group is connected to the gas conveying pipe between the filtering system and the high-pressure decompression system; the two gas cylinder switches are respectively mounted on the gas conveying pipes at the two ends of the high-pressu