This invention provides an oxygen-supplying breathing apparatus with no need of electrical power, which relates to an oxygen-supplying breathing apparatus being operable without electrical power and driven by the oxygen supply pressure from an oxygen supply end, comprising an oxygen supply valve unit communicated with the external oxygen supply end for switching on or off the oxygen supply end to output oxygen. An inspiration/expiration time setting valve unit are communicated between the oxygen supply valve unit and the oxygen supply end, which receives continuous oxygen supply from the oxygen supply end and intermittently outputs oxygen to the oxygen supply valve unit so as to drive the oxygen supply valve unit to intermittently switch on the oxygen supply end to intermittently output oxygen, thereby allowing the use of a breathing apparatus to provide oxygen to patients without using electrical power.
